Answer:
Explanation:
Pb(OH)2 + 2NaOH → Pb(OH)2 + 2NaOH
The balanced equation would be PbO + 2NaOH → Pb(OH)2 + Na2O
The reactant PbO is a lead oxide which is an acidic oxide, it reacts with NaOH, a strong base, to form Pb(OH)2, a lead hydroxide, which is a salt of lead, and Na2O which is sodium oxide , a base.
Puffy Chalmers was in his room, admiring his Mr. Drought mask, when his mother, Cookie Chalmers, barged into his room. She was so tired of the mask, she ripped it up and threw the pieces into a metal trash can. Then she pulled a bottle of acid out of her purse, and poured it on the mask pieces causing them to bubble, smoke, and change color. Did she change the mask physically or chemically? Explain your answer using evidence and your knowledge of physical and chemical changes. Help
She changed the mask chemically. Burning of the substance with acid is a chemical change.
A new substance with new qualities is created during burning, which is a chemical alteration that cannot be undone. A chemical change is the transformation of one substance into another, the emergence of new compounds with distinct properties, or any combination of these. It happens when two substances mix to create a new material. Baking soda and vinegar producing carbon dioxide, iron rusting, and wood burning are a few examples of chemical changes. The metabolization of food and the production of amylase from the combining of sugar and saliva are only two examples of the many chemical processes that the body produces.
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which of the following is a testable hypotheses?
O A. if I brush my teeth, I will get fewer cavities than if i don’t brush my teeth.
O B. it’s wrong not to brush your teeth before you have an important conversation with someone.
O C. Green toothpaste taste better than blue toothpaste or red toothpaste.
O D. smart, careful, healthy people always brush their teeth.
Answer:
A
Explanation:
because its the only one that can be tested
A compound is found to contain 59.94 % carbon, 13.44 % hydrogen, and 26.62 % oxygen by mass. What is the empirical formula for this compound
The empirical formula for this compound containing 59.94 % carbon, 13.44 % hydrogen, and 26.62 % oxygen by mass is C3H8CO.
Given the % of carbon = 59.94%
The % of hydrogen = 13.44%
The % of oxygen = 26.62%
If a percentage is provided, we will assume that the entire mass is 100 grams. As a result, each element's mass is equal to the percentage indicated. Then
the mass of carbon (m1) = 59.94g
The mass of hydrogen (m2) = 13.44g
The mass of oxygen (m3) = 26.62g
We know the molar mass of C = 12 g/mole
The Molar mass of H = 1 g/mole
The Molar mass of O = 16 g/mole
The moles of carbon = 59.94/12 = 4.995
The moles of hydrogen = 13.44/1 = 13.44
The moles of oxygen = 26.62/16 = 1.664
Divide each mole value by the lowest computed mole number to get the mole ratio.
For C = 4.995/1.664 = 3 , For H = 13.44/1.664 = 8 and For O = 1.664/1.664 = 1. Then the empirical formula = C3H8CO
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Select the correct answer. the zeroth law of thermodynamics describes the state where we can say what about the movement of heat between two substances?
a. the latent heat is increasing
b. the movement of heat is rapid
c. there is no movement of heat
d. the latent heat is decreasing
e. the movement of heat is slow
The zeroth law of thermodynamics describes the state where we can say what about the movement of heat between two substances
The Zeroth Law of thermodynamics is a basic law that describes the state in which two bodies are in thermal equilibrium. It states that if two bodies are in thermal equilibrium with a third body, then they are in thermal equilibrium with each other. In other words, it allows us to determine if two bodies are at the same temperature and if there is no heat flow between them. So, it describes the state where there is no movement of heat between two substances.
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a chloride of rhenium contains 63.6% rhenium. what is the formula of this compound?
A chloride of rhenium contains 63.6% rhenium. the formula of this compound is Re2Cl3.
The chemical trirhenium nonachloride has the formula ReCl3, which is occasionally also written as Re3Cl9. It is a hygroscopic solid that is dark red in color and insoluble in common solvents. The substance is significant in the development of inorganic chemistry since it was the first cluster compound to have metal-metal links. [1] It serves as the raw ingredient for the production of various rhenium complexes. Rhenium is an atomic number 75 chemical element with the symbol Re. It is a heavy, third-row transition metal in group 7 of the periodic table that is silvery-gray in color. Rhenium is one of the rarest elements in the Earth's crust, with an estimated average concentration of 1 part per billion (ppb).
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15.0 L of an ideal gas at 298 K and 3.36 bar are heated to 350 K with a new pressure of 4.90 atm. What is the new volume in litres
The new volume in litres is 13.29 L.
Given,
Temperature 1 (T₁) = 298 K
Volume 1 (V₁) = 15 L
Temperature 2 (T₂) = 383 K
Pressure 1 (P₁) = 3.36 atm
Pressure 2 (P₂) = 4. atm
By Ideal Gas Equation,
P₁V₁/T₁ = P₂V₂/T₂
⇒ (3.36*15)/298 = (4.90*V₂)/383
⇒50.4/298 = 4.90V₂/383
⇒ (50.4*383) / (298*4.90) = V₂
⇒ 19303.2/1460.2 = V₂
⇒13.29 L = V₂
New Volume will be 13.29 L.
Ideal gas law is a precise approximation of the behavioral of several gases under various situations in thermodynamics. The Ideal Gas Equation is a mathematical formula that combines empirical laws such as Charle's law, Boyle's law, Gay-law, Lussac's and Avogadro's law.
The equation characterizing the states of hypothetical gases stated mathematically by combinations of empirical or physical constants is known as the Ideal Gas Equation. It's also known as the universal gas equation. It is defined as follows:
"The ideal gas law seems to be the equation of state for a fictitious perfect gas. It is a decent approximation of the behavioral of various gases under numerous situations, while it has significant limitations".
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An oxide of chromium crystallizes with the following unit cell (chromium = gray; oxygen = red)(Figure 1) .
What is the formula of the oxide?
An oxide of chromium crystallizes with the following unit cell (chromium = gray; oxygen = red)(Figure 1) --CrO3
In order to determine the formula of the oxide, we need to determine the ratio of chromium to oxygen atoms in the unit cell. From the provided unit cell, we can see that there is one chromium atom (gray) in the center of the unit cell, and four oxygen atoms (red) surrounding it. This gives us a ratio of 1:4 chromium to oxygen, which simplifies to a ratio of 1:4 or 1/5. Therefore, the formula of the oxide is CrO4.An oxide is a chemical compound that contains at least one oxygen atom and one other element. Oxides can be either inorganic or organic, depending on the element that is combined with oxygen. Inorganic oxides are compounds composed of a metal and oxygen. They can be further classified as acidic, basic or neutral depending on the oxidation state of the metal atom. Examples of inorganic oxides include water (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen dioxide (NO2)
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Darwin observed how farmers and breeders produced many kinds of farm animals and plants. These plants and animals had traits that were desired by the farmers and breeders. He also noticed how the study of similar body structures and vestigial organs could add to the evidence of evolution. After performing several breeding experiments, he came to certain conclusions and formulated some theories. His theory of evolution and natural selection is the most accepted one.
What is the reason behind the acceptance of Darwin's theory?
Responses
A It is based on the practical example of Lamarck’s theoryIt is based on the practical example of Lamarck’s theory
B It is supported by its harmonizing with other views.It is supported by its harmonizing with other views.
C It is based on the ideas of earlier hypothesis and laws.It is based on the ideas of earlier hypothesis and laws.
D It is supported by practical evidence and examples.
The reason behind the acceptance of Darwin's theory is D It is supported by practical evidence and examples.
What is the theory of evolution proposed by Charles Darwin?The theory of evolution proposed by Charles Darwin is a well sustained model that explains how animals change in order to adapt to an ever-changing enviroment, which is supported by scientific evidence and observations.
Therefore, with this data, we can see that the theory of evolution proposed by Charles Darwin is well sustained by evidence obtained from experimentation and also observations of the natural world.
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How many of the carbons in the following compound are chiral center(s)? A) 0 B) 1 C) 2 D) 3 E) 4 or more
Answer:
3 (e
Explanation:
Which has the larger ionic size Li+ or K?
Answer: K
Explanation: as we move down the group new shells are added and this increases the distance between the outermost electron and the nucleus.
Determine the number of atoms of each element in the following: 3Ca(SO4 )
Answer:
3 Ca
3 S
12 O
Explanation:
You have 3 moles of Ca(SO4)
Therefore you multiply the subscript of each atom of the compound by 3.
Ca and S have a understood subscript of 1 so there are three of each.
There are 4 oxygen atoms in one mole of CaSO4 so in 3 moles there would be 4*3 so 12
A student standardized a solution of NaOH and found that the concentration was 0.544 M. They then used it to titrate a monoprotic acid. If 45.50 mL of the base was used, how many moles of acid were neutralized? (Do not report your answer in scientific notation)
The number of moles of a monoprotic acid neutralized is equal to 0.025 mol.
What is a neutralization reaction?A neutralization reaction can be defined as a reaction in which reaction of an acid and base generates salt and water. When a strong acid and a strong base react the salt can be neither acidic nor basic.
When monoprotic acid HA reacts with NaOH (a strong base), the resulting salt is NaA and water.
HA + NaOH → NaA + H₂O
Given, the concentration of NaOH = 0.544 M
The volume of the NaOH = 45.50 ml = 45.50 × 10⁻³
The number of moles of NaOH, n = M × V = 0.544 × 45.50 × 10⁻³ = 0.025 mol
The number of moles of HA monoprotic acid = moles of NaOH = 0.025 mol
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Petroleum is a fossil fuel containing many different carbon compounds. If the carbon atoms in petroleum have been in the ground for 100 million years, what fraction of the initial 14C atoms is still there
Thus, Option (C) Glucose has a maximum of 72 C-atoms per gram. The components of fossil fuels are decaying plants and animals.
These fuels may be burned to provide energy and can be found in the crust of the Earth. An example of a fossil fuel is coal, as well as oil and natural gas. Due to the hydrocarbons and other carbon-based compounds they contain, fossil fuels are valuable as energy sources. Any of a class of organic molecules made solely of carbon and hydrogen are known as hydrocarbons. The hydrogen atoms adhere to the carbon atoms, which serve as the "skeleton" or framework. Because they were generated from the petrified, buried remains of plants and animals that once lived millions of years ago, coal, crude oil, and natural gas are all referred to as fossil fuels.
The complete question is- Petroleum is a fossil fuel containing many different carbon compounds. If the carbon atoms in petroleum have been in the ground for 875 million years, what fraction of the initial 14C atoms is still there?
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Select the correct answer. what is the name of a system that converts thermal energy into a form of useful mechanical or electrical energy?
a. incubator
b. heat engine
c. centrifuge
d. vacuum column
e. spectrophotometer
Heat engine is a system that converts thermal energy into a form of useful mechanical or electrical energy.
In thermodynamics, the heat engine is a system which is able to convert the heat or thermal energy into mechanical or electrical energy which can be used in order to perform mechanical work. This is achieved by bringing the a particular working substance to a lower state temperature from a higher state temperature.
There are a different types of heat engines in which the Carnot engine possesses the maximum efficiency. Some examples of heat engines are firearms, thermal power station etc.
Hence, the correct option is b. heat engine.
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Identify the phrases that generally apply to molecular compounds. A. Contains metals and nonmetals B. Are often fades or liquids C. Have low melting points D. Contain ionic bonds E. Use covalent bonding
Answer is option C) Have low melting points.
Explanation:
As is common knowledge, small molecules make up molecular compounds, and these small molecules are held together by an intermolecular force. The intermolecular tensions in this situation are incredibly weak and simple to overcome when breaking it. Therefore, molecular compounds have low melting and boiling points because of weak intermolecular interactions.
What are molecular compounds?Chemical substances known as molecular compounds assume the shape of distinct molecules. Examples include common substances like carbon dioxide and water. These substances differ significantly from ionic substances like sodium chloride. When metal atoms give up one or more of their electrons to nonmetal atoms, ionic compounds are created. The resultant cations and anions are drawn to one another electrostatically.
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2H₂(g) + O2(g) → 2H₂O(g)
How many liters of H₂ are required to form 5 moles of H₂O at STP?
Answer:
The answer is 21.5 L
Explanation:
QUIZ 5: CHAPTER REVIEW The nuclear product of radioactive decay is called the daughter nuclide. True False
The nuclear product of radioactive decay is called the daughter nuclide.
True
What is radioactive?Radioactivity is a phenomenon in which particles such as alpha, beta and gamma rays are emitted from unstable atomic nuclei. This is due to the fact that the nucleus is unstable and requires a rearrangement of its protons and neutrons. Radioactive isotopes can be found in nature, or they can be artificially created. Radioactivity has many useful applications, such as medical imaging, cancer treatments, smoke detectors, and nuclear energy. It also has some potential dangers, such as radiation exposure and the risk of nuclear disasters.
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The activation energy of a first order reaction is 83. 5kJ/mol. The rate constant is 3. 54x10^-5s^-1 at 45 C. What is the rate constant at 65 C?
The rate constant at 65 C is k65= 4.8 x 10^-5 s^-1 .Below is the explanation for the answer
To find the rate constant at a different temperature, you can use the Arrhenius equation, which relates the rate constant to the activation energy and the temperature. The equation is:
k = A * e^(-Ea/RT)
where
k is the rate constant,
A is the pre-exponential factor (also known as the frequency factor),
Ea is the activation energy,
R is the universal gas constant,
T is the absolute temperature.
We are given that the activation energy is 83.5 kJ/mol and the rate constant at 45 C is 3.54 x 10^-5 s^-1. To find the rate constant at 65 C, we can substitute these values into the equation and solve for k.
k = A * e^(-Ea/RT)
k = 3.54 x 10^-5 s^-1 * e^(-(83.5 kJ/mol) / (8.314 J/mol*K * (45 + 273.15 K))
However, A is a constant that we don't know. To find the rate constant at 65 C, we can use the fact that the rate constant is proportional to the temperature. Therefore, we can find the ratio of the rate constants at 65 C and 45 C, then multiply it by the rate constant at 45 C to find the rate constant at 65 C.
k65/k45 = (T2/T1)^n
where
k65 is the rate constant at 65 C
k45 is the rate constant at 45 C
T2 is the temperature in Kelvin (65 + 273.15)
T1 is the temperature in Kelvin (45 + 273.15)
n is the order of the reaction, which is 1 in this case
we can find the rate constant at 65 C is:
k65 = k45 (T2/T1)^n
k65 = 3.54 x 10^-5 s^-1 * ( (65 + 273.15) / (45 + 273.15) )^1
k65= 4.8 x 10^-5 s^-1
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PLS HELP ASAP PLSSSS
Would greatly appreciate the help
9.0 mol Na2S reacts with 8.0 mol
CuSO4 according to the equation below:
Na2S + CuSO4
→
Na2SO4 + CuS
Considering only the 8.0 mol CuSO4,
how many moles of CuS form?
? mol CuS
Round your answer to the tenths place.
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.0 mol of CuS form when 8.0 mol CuSO[tex]_4[/tex] reacts.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. The stoichiometry represents the number of moles.
Na[tex]_2[/tex]S + CuSO[tex]_4[/tex]→ Na[tex]_2[/tex]SO[tex]4[/tex] + CuS
moles of Na[tex]_2[/tex]S =9.0 mol
moles of CuSO[tex]_4[/tex]=8.0 mol
Since CuSO[tex]_4[/tex] is limiting reagent
moles of CuS=8.0 mol
Therefore, 8.0 mol of CuS form when 8.0 mol CuSO[tex]_4[/tex] reacts.
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Calculate the maximum amount of picric acid (in grams) that can be obtained if 0.552mL of phenol (density
It is critical to develop a PheDH with specificity and high activity since it is crucial for the manufacture of chiral pharmacological intermediates and the detection of phenylketonuria.
Here, a PheDH gene, pdh, was discovered that encodes a novel BhPheDH with 61.0% similarity to the previously identified PheDH from Microbacterium sp. In comparison to the PheDH from Nocardia sp., the BhPheDH demonstrated superior stability in hot environments (40–70°C) and optimal activity at 60°C and pH 7.0. Additionally, sodium salt has the potential to greatly boost both its activity and thermostability. The residual activity of the BhPheDH was found to be 1.8-fold higher than that of the control group following incubation for 2 hours in 3 M NaCl at 60 °C (without NaCl).
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What do Nitrogen, Oxygen, and Fluorine have in common, with regards to their electronegativity and position in the periodic table
The elements that are nitrogen, oxygen and fluorine all of them exist as diatomic gases at room temperature.
There are total seven diatomic elements that are written as follows: hydrogen (H), nitrogen (N), oxygen (O), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). The formation of diatomic gases is done by making up two atoms of the same gas. For example, the formula for nitrogen gas is N2, the formula for oxygen gas is O2 and the formula for Fluorine gas is F2. The word diatomic has other synonym which is known as heteronuclear. The position of all these three elements in the periodic table is different so their electronegativities, the only common factor is that they exist as a gas.
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A beautyberry is a type of shrub that grows well in the southern United States. Some students have a small beautyberry shrub that is growing near their school. They record the number of berries, ripe or unripe, and the number of flowers at different times throughout the year.
Table. Column headings. Month, ripe berries, unripe berries, flowers. September, 9, 4, 2. October, 5, 10, 4. November, 5, 7, 3. December, 2, 3, 1. February, 3, 2, 0. March, 6, 11, 5. April, 12, 5, flowers 9. June, 3, 8, 2.
Which statement best explains what is shown in their data?
Choose the correct answer.
Responses
A.The beautyberry relies on wind to spread its seeds.
B..The beautyberry relies on one type of animal to eat the berries.
C.The beautyberry uses asexual reproduction to make new plants.
D.The beautyberry increases its chances of reproduction because its berries do not all become ripe at the same time.
Note that statement best explains what is shown in the above-tabularized data is: "The beautyberry increases its chances of reproduction because its berries do not all become ripe at the same time. (Option D)
What is the rationale for the above answer?The statistics in the above table appear to reflect the ripening of berries and the number of blossoms of a plant, presumably called beautyberry. It can be noticed that the amount of ripe berries and blossoms varies each month.
This implies that the beautyberry does not produce all of its berries at once, but rather over the course of several months. This might boost the odds of reproduction by providing a food supply for animals and birds for a longer length of time.
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How many moles of H3PO4 form from 9 mol P4O10
According to the given chemical equation and stoichiometry of it , 36 moles of H₃PO₄ are formed from 9 moles of P₄O₁₀.
What is stoichiometry?It is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.
As per the reaction, 1 mole of P₄O₁₀ produces 4 moles of H₃PO₄, thus 9 moles of P₄O₁₀ will produce 9×4=36 moles of H₃PO₄.
Thus,36 moles of H₃PO₄ are formed from 9 moles of P₄O₁₀.
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Answer:36
Explanation:
taking the class just got it right
The pressure of hydrogen sulfide gas in a container is 35,650Pa. What is this pressure in torr (1 atm = 101,325 Pa = 760torr)?A. 46. 91 torrB. 267. 4 torrC. 351. 8 torrD. 3612torrE. 27,090 torr
In a container, the pressure of hydrogen sulfide gas is 267.4 torr.
What is pressure?The force of all gas particle/wall collisions divided by the area of the wall is defined as pressure (P): Pressure is one of the primary observable quantities of this phase of matter; it is exerted by all gases. The amount of force exerted per area is described as pressure. Pressure is defined as force divided by area. The pressure from snow on a roof, for example, would equal the weight of the snow divided by the area of the roof. In chemistry, pressure is often generated by gases. When you blow up a balloon, you fill it with gas.
Here,
pressure of hydrogen sulfide gas= 35650 Pa
1 torr=133.33 Pa
=35650/133.33
=267.38 torr
The pressure of hydrogen sulfide gas in a container is 267.4 torr.
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How many times more acidic is a solution with a pH of 2 compared with one with a pH of 5 Explain.
Using a logarithmic scale with 7 as neutral, lower values are more acidic and higher values are more alkaline, the acidity or alkalinity of a solution is expressed. where c is the number of moles of hydrogen ions present per litre. So pH 2 is 1000 times stronger than pH 5, and vice versa.
A pH of 2 is how much more acidic than a pH of 5.For instance, a pH of 2 is 10,000 times more acidic than a pH of 3 and a pH of 5 is 10,000 times more acidic. Ten times as alkaline as a pH of 10 is a pH of 11.
How many times more acidic is a pH 2 solution compared to a pH 9 solution?Each whole pH value is ten times more acidic than the next higher value since the pH scale is logarithmic.
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There are 4 wavelengths that are emitted from a Hydrogen atom that can be seen by the human eye. Two of the wavelengths are the same color. What colors are they
Answer:
a) red, blue, and violet
b) orange, yellow, and green
C) red, orange, and yellow
D) blue, indigo, and violet
PLS HELP ME WITH THIS QUESTION answer all blanks
The balanced chemical equation is N₂ + 3 H₂[tex]\rightarrow[/tex] 2 NH₃ which gives the formation of ammonia.
What is chemical equation?
Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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At room temperature I2(s) is a molecular solid. Which of the following provides a characteristic of I2(s) with a correct explanation ?
(A) It has a high melting point because it has (B) It is hard because it forms a three-dimensional covalent network
(C)It is not a good conductor of electricity because its valence electrons are localize in bonding and nonbonding pairs. (D) It is very soluble in water because its molecules are polar.
At room temperature I₂(s) is a molecular solid. the correct explanation is : (C)It is not a good conductor of electricity because its valence electrons are localize in bonding and nonbonding pairs.
The Iodine , I₂ is the example of the molecular solid. the iodine is the good conductor of the electricity due to the valence electrons that are localized in the bonding pairs and the non bonding pairs. the iodine is the element in the periodic table with the atomic number 53. the iodine is the non metallic solid at the room temperature.
The iodine exists as the diatomic form. the each iodine molecules present as the two iodine as I₂ . this is the reason it is called as molecular solid.
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What element has the electron configuration 1 s 2 2 s 2 2 p 6 3 s 2 3 p 2 ?
Phosphorus, which has the atomic number 15 and is located in period 3 and group 15 of the periodic table.