Answer:
Hydrogen and helium are placed in different groups in the periodic table because they have different atomic numbers and different chemical properties......................................
Explanation:
In the periodic table, the elements are arranged according to their atomic number, which is the number of protons in the nucleus of an atom. The elements are also organized into groups, or families, based on their chemical properties.
Hydrogen and helium are placed in different groups in the periodic table because they have different atomic numbers and different chemical properties. Hydrogen is placed in group 1a, also known as the alkali metals, because it has a single valence electron, which is an electron that is involved in chemical bonding. Helium, on the other hand, is placed in group 8a, also known as the noble gases, because it has a full valence shell, which means that it does not readily form chemical bonds.
It is important to note that the arrangement of elements in the periodic table is not based on the choices or preferences of the elements themselves, but rather on their intrinsic properties, such as their atomic number and chemical behavior.
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Answer:ok
Explanation:why you take picture upside down
In Belize City, on a cloudy day the temperature is 24 degrees Celsius. This is equal to how much in Fahrenheit. *
Pick 1 answer, please help!
I’m completely lost on these stoichiometry problems
Answer:
1) 4.21 x 10^24 molecules of Fe2O3
2) 36.416g of O2
Explanation:
1) First, find moles of Fe2O3 by using the mole ratio of 3:2. Fe2O3 has a coefficient of 2, and O2 has a coefficient of 3 thus making their mole ratio 2:3. Then, multiply 10.5 moles of O2 by 2/3 which equals 7 moles of Fe2O3. Finally, convert moles of Fe2O3 to molecules by multiplying it by Avogadro's number.
10.5 mol x 2/3= 7 mol Fe2O3
7 mol multiplied by 6.02 x 10^23 = 4.21 x 10^24 molecules
2) First, convert grams of KClO3 to moles by dividing it by its molar mass(approximately 122.5 g), which equals .759 mol. Then find moles of O2 by multiplying .759 mol KClO3 by the mole ratio of O2 to KClO3, which is 3:2. That equals 1.138 moles of O2. Finally, convert moles to grams by multiplying 1.138 mol by the molar mass of O2 (approximately 32g). 36.416g of O2 is your final answer.
93g KClO3/ 122.5g = .759 mol KClO3
.759 mol x 3/2= 1.138 mol O2
1.138 mol x 32g= 36.416g O2
Answer:
See Explanations ... I'll have to deliver my explanation in two posts. One is beyond the limits allowed.
Explanation:
Stoichiometry is very easy if you understand the relationship between the 'mole' and the balanced chemical equation. Let's start by defining the 'mole'
The 'mole' of substance is the mass of substance (element or compounds) that contains 1 Avogadro's Number ( = 6.02 x 10²³ ) of particles. The mass of substance that does contain 1 Avogadro's Number of particles is 1 formula weight of substance (also, molecular weight of substance). That is,
1 mole = 1 formula wt. = 1 mole weight = 1 Avogadro's Number = 6.02 x 10²³ particles of substance.
So, assuming you can determine formula weight then that value expressed in terms of grams is a 'Gram Formula Weight'; that is, 1 GFW = 1 mole wt.
At this point it is assumed that you understand how to balance simple chemical equations by inspection. That is, by the Law of Mass Balance ...
total mass of reactants = total mass of products
In problem 1 you are given iron (Fe) + molecular oxygen (O₂) => iron(III) oxide (Fe₂O₃) ... 4Fe + 3O₂ => 2Fe₂O₃ ... ∑mass R = ∑mass P.
Now, focus on the coefficients of each substance, that is, 4 for Fe, 3 for O₂ and 2 for Fe₂O₃. These values (coefficients) are moles of each substance in a special type of equation called the 'Standard Equation'. The Standard Equation is one which when balanced its coefficients are in the smallest whole number mole ratio of substance. That is the equation above is showing 4 moles of Fe, 3 moles of O₂ and 2 moles of Fe₂O₃. This is important in that most balanced equations that will be given in textbook problems will be in Standard Form.
From the Standard Form, the coefficients can be doubled, or divided in half, or whatever multiple or fraction one desires. The reaction would still perform in correct proportions. However, the multiples or fractions would not be in Standard Form. Most, if not all, stoichiometry problems will provide only the Standard Form.
Example, let's take the given equation above (from problem 1)
4Fe + 3O₂ => 2Fe₂O₃.
Both of the following are in correct proportions and will react with respect to the proportions YOU choose ...
(multiply by 2) => 8Fe + 6O₂ => 4Fe₂O₃.
(dividing by 2) => 2Fe + 3/2O₂ => Fe₂O₃.
Both are balanced and conform to the Law of Mass Balance but are not in Standard Form. Oh, and the Standard Form equations are assumed to be at 0°C and 1 atm, even if not specified in the problem. You may not need that now, but will become important in Gas Laws.
Let's move on to stoichiometry calculations. There are several methods being taught within the chemed. community, but I'm going to focus only on using mole ratios.
My approach begins with this rule => convert reaction data to moles, solve using mole ratios and convert to needed dimension at the end of the problem. This will simplify a lot of problems once you understand what it's about.
OK, for problem 1 ...
How many molecules of Fe₂O₃ can be produced from 10.5 moles of O₂?
Given the Standard Form equation 4Fe + 3O₂ => 2Fe₂O₃.
Now, write (neatly) the equation and list the givens under the specific substances ...
4Fe + 3O₂ => 2Fe₂O₃.
ex* 10.5 moles ? molecules note: ex* = excess (not used)
In this problem, since O₂ is already in terms of moles no conversion needed.
What you need to focus on is the relationship between the coefficients of O₂ and Fe₂O₃. Note that the coefficient of Fe₂O₃ is SMALLER than the coefficient of O₂. This means that the number of moles of Fe₂O₃ formed will be smaller than moles of O₂ given, that is 10.5 moles. How much smaller? Easy Calculation => Take the coefficient of O₂ and the coefficient of Fe₂O₃ and make a ratio of the numbers that will make 10.5 SMALLER. That is, you should use 2/3(10.5) to get a smaller number, not 3/2(10.5) because that would give a larger number and inconsistent with the ratio given in the balanced equation.
So, moles of Fe₂O₃ produced = 2/3(10.5) moles Fe₂O₃ = 7 moles Fe₂O₃. Note that 7 moles is smaller than 10.5 moles.
Now, the number of molecules of Fe₂O₃ is also an easy calculation.
Remember that 1 mole contains 6.02 x 10²³ particles, then 7 moles would contain ...
= 7 moles Fe₂O₃ x 6.02 x 10²³ molecules Fe₂O₃/mole Fe₂O₃
= 4.21 x 10²⁴ molecules Fe₂O₃.
Go to 2nd post for problem 2 solution.
3. Universal indicator is used to
determine the pH of a solution. Which
statement is correct?
A. Universal indicator turns red in
strong alkali.
B. Universal indicator turns blue in
strong acid.
C. Universal indicator turns orange in
weak acid.
Answer:
C.Universal indicator turns orange in
weak acid.
Explanation:
option A and B are incorrect coz universal indicator turns red in strong acid and in strong alkali (base) it turns blue
A pot of water at 25°C is placed over a flame until it has boiled away. Which way is energy being transferred between the system and the surroundings? *
Answer:
See explanation
Explanation:
According to the law of conservation of energy; energy is neither created nor destroyed but is converted from one form to another.
This means that energy can not be lost, we can trace the transfer of energy between a system and its surroundings.
When a pot of water at 25°C is placed over a flame until it has boiled away, energy is transferred from the pot (the system) to the surroundings hence the temperature of the surroundings rises accordingly.
Mention any four names of conservation area?
Answer:
pi r squared
Explanation:
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What will happen to buildings, statues and canyons where water flows through them over many years?
Answer:
Water gradually degrades them until the metal parts rust and the other materials deteriorate.
Explanation:
Un elemento hipotético posee un número másico igual 45 y en estado neutro (sin carga), tiene 22 electrones. Indicar el número de neutrones que posee dicho elemento hipotético:
Answer:
23 neutrones.
Explanation:
Bajo el modelo atómico actual, los átomos están hechos de neutrones (Particulas sin carga y número másico de 1), electrones (Partículas con carga de -1 y número másico de 0) y protones (Partículas con carga de +1 y número másico de 1).
El elemento contiene 22 electrones y carga neutra. Esto significa que contiene igual número de protones:
22 protones.
Como el número másico es de 45 y los protones aportarán solo 22 de número másico, el elemento debería tener:
23 neutrones para completar así, el número másico.
Which statement explains why many scientists believe that carbon dioxide has likely contributed more to global warming than other greenhouse gases?
Answer:
C. Carbon dioxide has increased as a result of increased human activities.
Explanation:
THESE ARE THE OPTIONS FOR THE QUESTION BELOW
A. Carbon dioxide is emitted from fertilizers used in farming.
B. Other greenhouse gases trap more heat than carbon dioxide.
C. Carbon dioxide has increased as a result of increased human activities.
D. Carbon dioxide is emitted from commercial refrigeration.
Global warming can be regarded as
long-term heating of climate system of the Earth, this has been a point if observation even as far as pre-industrial period arround 1850. This global warming can be attributed to activities such as human activities as well as primarily fossil fuel burning, and as a result of this there is rise in heat-trapping, increase in greenhouse gas levels arround the atmosphere of the Earth. Human activities that brings about increase of Carbon dioxide concentration in the atmosphere are ;
✓ burning of oil as well as coal and gas,
✓deforestation
Hence, many scientists believe that carbon dioxide has likely contributed more to global warming than other greenhouse gases as a result of increase in Carbon dioxide which is as a result of increased human activities.
Greenhouse gas, any gas that has the property of absorbing infrared radiation (net heat energy) emitted from Earth's surface and reradiating it back to Earth's surface, thus contributing to the greenhouse effect. Carbon dioxide, methane, and water vapour are the most important greenhouse gases.
Answer:
C
Explanation:
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The endocrine system's role is to send out chemical messages so as to regulate bodily activities. It determines how and when you grow, when you hit puberty and how much your body changes, and even what mood you're feeling right now.
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Answer:
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The maps show that northern areas should get
Answer:
We might need more information too answer that question...
Explanation:
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PLEASE HELP
How does increasing the amount of greenhouse gases affect the earth?
It causes more hurricanes and tornadoes.
It lowers the earth's global temperature.
It causes fewer thunderstorms.
It raises the earth's global temperature.
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I needed the answer for the test and he is correct
please help me with this question
Answer:
Magnesium Hydroxide or Milk of Magnesia
Explanation:
The chemical sign for Magnesium is Mg, and OH automatically means Hydroxide.
You are given three liquids. You know that one of them is a suspension, one is a solution with nonelectrolytes, and the other is a solution with electrolytes. Describe the process by which you would differentiate between the three.
Answer:
decant/ filter then decompose the electrolytes by electrolysis
Explanation:
Differentiation of suspension solution is done by filtering and differentiation of electrolyte and non-electrolyte solution is done by electrolysis process.
What is electrolysis process?Electrolysis process is used to decompose the any electrolyte present in any solution into their constitute ions towards the cathodes and anodes under the electric flow of current.
Process which is required to differentiate suspension solution is filtering, because in this solution suspended insoluble particles are present which get filtered. Now to differentiate between non electrolyte and electrolyte solution we will use the electrolysis process, as non electrolyte solution do not show any behavior in this.
Hence, we use filtering and electrolysis process for the differentiation.
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6
0/1 point
If you have 1.0 mole of each of the following compounds, which will have the most molecules?
Х
NI3 (nitrogen triiodide)
KCI (potassium chloride)
Lici (lithium chloride)
O C2H2 (ethyne)
O They all have the same number of molecules.
7
1/1 point
fn 35 moles of Iron (Fe)?
Answer:
6. They all have the same number of molecules.
7. 19.5 g
Explanation:
6. From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules i.e
1 mole = 6.02×10²³ molecules
Considering the question given above, each compounds has just 1 mole. Thus, they will also have the same number of molecules.
7. Determination of the mass of iron (Fe)
Number of mole of Fe = 0.35 mole
Molar mass of Fe = 55.85 g/mol
Mass of Fe =?
Mass = mole × molar mass
Mass of Fe = 0.35 × 55.85
Mass of Fe = 19.5 g
Thus, the mass of 0.35 mole of iron (Fe) is 19.5 g
How many grams of KOH are required to make 125mL of a 0.50M solution?
Answer:3.51 g
Explanation: M(KOH)= 39.10 + 16 + 1.008 = 56.108 g/mol
Amount of substance is n= m/M = cV and mass m= McV
Volume in litres is 0.125 l
Which question is a scientist who studies the genetic engineering of crops most likely attempting to answer?
A. How can a more stable supply of crops be created?
В. How can natural selection create better crops?
С. How can crops be grown without a need for light?
D. How can the genetic variation of crops be increased?
Answer:
i think that it is A
Explanation:
the other ones did not make as much sense
A scientist who studies the genetic engineering of crops most likely attempting how more stable supply of crops be created. so, option A is correct.
What is genetic engineering ?Genetic engineering, often known as genetic alteration, is a technique that modifies an organism's DNA using technology developed in labs. This could entail altering a single base pair (A-T or C-G), erasing a section of DNA, or incorporating a new DNA sequence.
In order to fix genetic flaws and hence prevent or treat hereditary illnesses, gene therapy aims to change specific genes.
The goal of genetic engineering is to alter the genes to increase the organism's capabilities beyond what is typical.
The term "genetic engineering" originally applied to a number of methods for modifying or altering living things through their heredity and reproductive processes.
Thus, option A is correct.
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what tools are used to predict blizzards
Answer:
someone people use Doppler radar
Explanation:
Mass = 200 g Volume = 20 cm3 What is the density?
Answer: 156
Explanation:
why does the atmosphere weigh so much
Answer:
Because the Earth's gravity acts on the atmosphere and holds it down, just as it does all other objects. The weight of the atmosphere is estimated to be about 5.75 quadrillion (5,750,000,000,000,000) tons. Air pressure is the "push" of the atmosphere on the Earth's surface.
Can someone help? Please show work for each one!
Answer:
2)====We assume you are converting between moles CaCl2 and gram. You can view more details on each measurement unit: molecular weight of CaCl2 or grams This compound is also known as Calcium Chloride. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles CaCl2, or 110.984 grams
110.98 g/mol
The molar mass of CaCl2 is 110.98 g/mol.
3)The molar mass of Na3 PO4 is 163.9 g/mol. To determine the molar mass, add the atomic mass of all the atoms.
One idea for avoiding a catastrophic collision of space debris with Earth is the use of missile-like projectiles to knock the object off course or deflect it. How can scientists be sure to create an impact with enough kinetic energy to change a meteoroid’s course? What factors should they consider? HELP :,)
SOMEONE PLEASE HELP ME ON THIS QUESTION ASAP!!! NO LINKS
Answer:
as for my answer is C.....
can someone help with this???
Answer:
2Mg(s) +O₂(g) → 2MgO(s)
Explanation:
Mg(s) +O₂(g) → MgO(s)
When a chemical equation is balanced, the number of atoms of each element is equal on both sides of the arrow. We usually balance O and H last.
In this case, the number of Mg atoms is equal on both sides. Thus, let's move on to balance the O atoms. On the left side, there are 2 O atoms, while there is only 1 O atom on the left side. Thus, write a '2' in front of MgO.
Mg(s) +O₂(g) → 2MgO(s)
Now, the number of Mg atoms is not equal. Write a '2' in front of Mg to balance it.
2Mg(s) +O₂(g) → 2MgO(s)
The equation is now balanced with 2 Mg atoms and 2 O atoms on each side.
Convert 213.62 grams of xenon gas at STP to L.
1. What is the coefficient of the scientific notation answer ?
2. What is the exponent of the scientific notation answer?
3. How many significant figures are there in the answer?
4.What is the right most significant figure in the answer ?
Answer: The coefficient is 3.645
The exponent is 1
There are 4 significant digits
The rightmost significant figure is 5
Explanation:
Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.
For example : 5000 is written as [tex]5.0\times 10^3[/tex]
According to avogadro's law, 1 mole of every gas contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles, occupy 22.4 L at STP and weighs equal to its molecular mass.
131.29 g of Xe occupy = 22.4 L at STP.
Thus 213.62 g of [tex]Xe[/tex] occupy = [tex]\frac{22.4}{131.29}\times 213.62=36.45L[/tex] at STP.
Scientific notation = [tex]3.645\times 10^1L[/tex]
The coefficient is 3.645
The exponent is 1
There are 4 significant digits
The rightmost significant figure is 5
why a dipole develops in a molecule
Answer:
Dipole interactions occur when partial charge form within a molecule because of the uneven distribution of electrons.polar molecules align so that the positive end of one molecule interacts with the negative end of another molecule.
Answer: Uneven distribution of electrons in a
Molecule.
Explanation: Q. What’s the dipole-dipole interaction ?
SOL.-
CONCEPT-
Dipole-dipole Forces -
Intermolecular interactions are necessary for the stability of the molecule. There are many types of intermolecular forces, and dipole-dipole forces are part of these forces them.
Dipole-dipole forces, also known as dipole-dipole interactions. The electrostatic forces between two permanent polar molecules is known as dipole- dipole force. Generally, the positive side of one molecule is attracted to the negative side of another molecule. The two molecules come closer, and add for increasing the stability of the substance. This type of interaction is different from a regular ionic bond or a covalent bond because there is no transfer or sharing of electrons.
Causes of a Dipole-dipole Interaction-
Dipole-dipole interaction arises due to the unlike distribution of electrons in a molecule. The electrons are assembled at one end of the molecule. Thus, the molecule get a partially negative charge at one end and a partial positive charge at the another end. That process making them polar. Generally, two polar molecules with opposite nature charges will attract one another.
Diagram-
Reference link.- https://brainly.com/question/22790347
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____H3PO4 + ____ KOH --> ______K3PO4 + ____H2O can someone please balance that chemical equation?
Answer:
H3PO4 + 3KOH ----> K3PO4 + 3H2O
Explanation:
The valency of K element is + 1 while that of PO4 compound is -3
Hence, at least 3 K atoms are needed to combine with PO4 to form K3PO4 compound.
Hence, the revised equation will be
H3PO4 + 3KOH ----> K3PO4 + 3H2O
Now, the number of atoms and charges of each element is a given equation are equal on both the left and right hand side.
What does the word omniphobic mean?
Answer:
Special type of surface that repels liquid
Explanation: