Answer:
Scientists used the model to make predictions. Sometimes the result of the experiments were a surprise and they did not fit with the existing model!
How is an unknown oxidation state of an element within a compound
determined?
O A. It will be the same in the products as in the reactants.
B. It will be the same as the charge on the compound.
C. It is always the same as the most likely oxidation state.
ОС
OD. It is determined from known oxidation states of other elem
Answer:
it is determined from known oxidation states of other elements
what type of element is always radioactive?
NEED HELP ASAP!
What is the wavelength of a wave that has a frequency of 6.1 x 10^9 Hz? Remember that c = 2.998 x 10^8 m/s.
A.) 52m
B.) 5.2m
C.) 0.49m
D.) 0.049m
Answer:
speed = wavelength × frequency
wavelength = Speed/frequency
wavelength = 2.998 x 10^8 m/s ÷ 6.1 x 10^9 Hz
wavelength = 0.049m
How do I learn a subject easier
Say out loud what you want to remember.
Take notes by hand, not on a computer.
Chunk your study sessions.
Test yourself. A lot.
Change the way you practice.
Exercise regularly.
Get more sleep.
Learn several subjects in succession.
what is the mass in grams for 7.14x10^3 mol of PCI3?
Answer:
980,536.2 grams
Explanation:
The mass of a compound is equal to its moles times its molar mass.
The molar mass of PCl3 is 137.33 g/mol
137.33 x 7.14 x 10^3 = 980,536.2
20 Infer Check the box to show which would tell you for sure if you had a sample of real gold.
Color of your sample. Yes No
What happens when you strike your sample with a hammer.
The location where your sample was found.
Answer:
C but read the limitation
Explanation:
Gold sample
Color wouldn't tell you much. In fact it may fool you. Fool's Gold is the same color as gold.
Gold is very malleable. That's what hitting gold with a hammer will do. It tends to shape the gold without destroying it into lots of pieces. A lot of yellow things have that property.
If only it was that simply. Yes if you are sure there is gold in that location. You have to pick this answer, because the other 2 don't work. So this is possible, but not the best way. The best way is to subject the sample to chemical treatment. If you are left with a yellow sample, then you could make the case for it being gold.
Use the word bank below to complete the statement. Not all of the words will be used.
Word Bank:
sum. Enthalpy. Heat. Total.
Temperature. Moles. -ΔH. +ΔH.
Hess’s Law describes how the ____ energy of a reaction consists of the ___ of the energy changes of the individual step reactions.
Answer:
Hess’s Law describes how the __Heat__ energy of a reaction consists of the _Enthalpy__ of the energy changes of the individual step reactions
Explanation:
Hess law is a legendary law which is given by
[tex]\\ \rm\Rrightarrow ∆H_{net}=\sum \delta H_r[/tex]
let's say these four solutions have the same concentration, which one has the highest freezing point?
a) calcium chloride
b) glucose
c) sodium chloride
d) ammonium chloride
Answer:
c) Sodium chloride
How can you tell if a substance is an acid or base?
Answer:
To determine whether a substance is an acid or a base, count the hydrogens on each substance before and after the reaction. If the number of hydrogens has decreased that substance is the acid (donates hydrogen ions). If the number of hydrogens has increased that substance is the base (accepts hydrogen ions
compare fission and fusions.
Type the correct answer in the box. given: cac2 n2 → cacn2 c in this chemical reaction, how many grams of n2 must be consumed to produce 265 grams of cacn2? express your answer to three significant figures. the reaction requires grams of n2.
The amount, in grams, of [tex]N_2[/tex] that will be consumed to produce 265 grams of [tex]CaCN_2[/tex] will be 80.61 grams
Stoichiometric calculationFrom the equation of the reaction:
[tex]CaC_2 + N_2 --- > CaCN_2 + C[/tex]
The mole ratio of [tex]N_2[/tex] consumed to [tex]CaCN_2[/tex] produced is 1:1.
Mole of 265 grams of [tex]CaCN_2[/tex] = 265/92.11 = 2.88 moles
Equivalent moles of [tex]N_2[/tex] = 2.88 moles
Mass of 2.88 moles [tex]N_2[/tex] = 2.88 x 28.02 = 80.61 grams
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Based on your research, which source of energy do you think best meets the needs of society? Defend your answer in 50 to 100 words.
Currently, fossil fuels meet the 80% of needs of the society. But it is a non-renewable source, and it will extinct soon. The leading renewable source is wind power.
What is the non-renewable and renewable source?Non-renewable energy are the energies that will require a thousand of years to make and ones extinct, will not be prepared.
Renewable energy sources can be prepared again and again, examples are wind, solar, hydropower.
Thus, the fossil fuel and wind power is the leading source of energy that meets the needs of society.
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NEED THIS ASAP PLEASE HELP!! WILL GIVE 10 PTS!! WILL MARK BRAINLIST!!
The base Ba(OH)2 neutralizes the acid H2SO4 according to the equation below. What salt is produced?
H2SO4 + Ba(OH)2 -->
A. BaSO4
B. BaH2
C. BaH2S
D. BaO4
Answer:
According to the equation below salt is produced by BaH2s
Answer:
I think b is the correct answer
Please Help I need an explanation on how to do this
Balanced equation(That should be NaClO_3)
[tex]\\ \rm\Rrightarrow Cl_2+2NaOH\longrightarrow NaCl+NaClO_3+H_2O[/tex]
Remember that it's a ionic equation not general equation
So
We have to balance it accordingly
Answer:
Balanced equation(That should be NaClO_3)
\begin{gathered}\\ \rm\Rrightarrow Cl_2+2NaOH\longrightarrow NaCl+NaClO_3+H_2O\end{gathered}⇛Cl2+2NaOH⟶NaCl+NaClO3+H2O
Remember that it's a ionic equation not general equation
So
We have to balance it accordingly
what is the molarity of liters of an aqueous solution that contains 0.50 mole of potassium iodide, KI
Answer:
The molarity of 2.0 liters of an aqueous solution that contains 0.50 mol of potassium iodide is 0.25M.HOW TO CALCULATE MOLARITY:The molarity of a solution can be calculated by dividing the number of moles by its volume. That is;Molarity = no. of moles ÷ volumeAccording to this question, 2.0 liters of an aqueous solution that contains 0.50 mol of potassium iodide. The molarity is calculated as follows:Molarity = 0.50mol ÷ 2LMolarity = 0.25MTherefore, the molarity of 2.0 liters of an aqueous solution that contains 0.50 mol of potassium iodide is 0.25M.Learn more about molarity at: brainly.com/question/2817451
Explanation:
Mark me brainliest please!!! I spent a lot of time on this!!
A gas occupies a volume of 140. mL at STP. What is the volume of the gas at 25°C and 3.00 atm
At STP
pressure is 1atmSo
Apply Boyles law
P1V1=P2V2140(3)=1V2420=V2V2=420mL1 Identify Draw an example of a force acting on an object.
Answer:
Answer below
Explanation:
Just draw a photo of someone pushing an object across a table. Your push is the force acting on the object you're pushing.
How many grams of sodium hydroxide, NaOH, are needed to make 355.0 mL of a 4.75M solution? The molar mass of NaOH is 40.00 g/mol
Answer:
4198.97404999
Explanation:
In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together.
Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance.
If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom (or group of atoms) in the formula by the formula weight and multiplying by 100.
Continued deforestation will most likely lead to _______. a. a decrease in the number of endangered species b. an increase in the number of endangered species c. an increase in the number of oil and chemical spills d. a decrease in glacial melting please select the best answer from the choices provided a b c d
Deforestation often leads to an increase in the number of endangered species of plants and or animals.
What is deforestation?Deforestation refers to the conversion of forests to non-forest uses. In other words, it is the removal of forest layers for non-forest reasons.
Since forests represent a hotspot for plant and animal biodiversity, their removal automatically means a decrease in biodiversity.
Endangered species are species of plants and animals that are under the threat of going extinct either due to natural or anthropological effects.
Thus, deforestation often leads to an increase in the number of endangered species.
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Answer:
b
Explanation:
H+ ion concentration of 2.5 x 10-5
Answer:
What is the hydrogen ion concentration of a solution labeled "Solution A", whose pH is 5.60?
Tutorial
In this problem we are given pH and asked to solve for the hydrogen ion concentration. Using the equation, pH = − log [H+] , we can solve for [H+] as,
− pH = log [H+] ,
[H+] = 10−pH,
by exponentiating both sides with base 10 to "undo" the common logarithm. The hydrogen ion concentration of "Solution A" is,
[H+] = 10−5.6 ≈ 0.0000025 = 2.51 × 10−6 M.
We can always check our solution by computing −log (2.5 × 10−6) ≈ 5.6.
Zinc metal is added to hydrochloric acid to generate hydrogen gas and is collected over a liquid whose vapor pressure is the same as that of pure water at 20.0°C (18 torr). The volume of the mixture is 1.7 L, and its total pressure is 0.788 atm. Determine the number of moles of hydrogen gas present in the sample.
Answer:
About 0.054 moles.
Explanation:
Apply the ideal gas law. Recall that:
[tex]\displaystyle PV = n RT[/tex]
Solve for n, the number of moles:
[tex]\displaystyle n = \frac{PV}{RT}[/tex]
Determine the pressure of the hydrogen gas. Recall that by Dalton's Law of Partial Pressures, the total pressure is equal to the sum of the partial pressures of each individual gas:
[tex]\displaystyle P_T = P_\ell + P_\text{H$_2$}[/tex]
Convert the vapor pressure of the liquid to atm (1.00 atm = 760. torr):
[tex]\displaystyle 18\text{ torr} \cdot \frac{1.00\text{ atm}}{760.\text{ torr}} = 0.024\text{ atm}[/tex]
Therefore, the partial pressure of the hydrogen gas is:
[tex]\displaystyle \begin{aligned} P_T & = P_\ell + P_\text{H$_2$} \\ \\ (0.788\text{ atm}) & = (0.024\text{ atm}) + P_\text{H$_2$} \\ \\ P_\text{H$_2$} & = 0.764\text{ atm}\end{aligned}[/tex]
Therefore, the number of moles of hydrogen gas present is (the temperature in kelvins is 273.15 + 20.0 = 293.2 K):
[tex]\displaystyle \begin{aligned} n & = \frac{PV}{RT} \\ \\ & = \frac{(0.764\text{ atm})(1.7\text{ L})}{\left(0.08206 \text{ }\dfrac{\text{L-atm}}{\text{mol-K}}\right)(293.2\text{ K})}\\ \\ & = 0.054\text{ mol H$_2$} \end{aligned}[/tex]
how do energy sources poly a role in the rock formation?
Sun (radiation), winds (eolic) and water (hydraulic) are all sources of energy that work together during rock formation.
What is rock formation?The rock formation is a very slow process that occurs at a geological time, which may take millions of years.
During this period, rocks are shaped by different types of energy, especially radiation and erosion (wind and water bodies)
In conclusion, the sun (radiation), winds (eolic) and water (hydraulic) work together during rock formation.
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What is the equilibrium constant equation for the chemical process below?
2A + B2 —> A₂B2
Let's see
[tex]\\ \rm\dashrightarrow k=\dfrac{Concentration\:of\: products}{Concentration\:of\: reactants}[/tex]
[tex]\\ \rm\dashrightarrow k=\dfrac{\left[A_2B_2\right]}{\left[A\right]^2\left[B\right]}[/tex]
22. A mixture of gases contains 1.0 atm of neon, 2.0 atm
of Argon, and 6.0 atm of xenon. What is the total pressure
in the container?
The total pressure of the mixture of the nobles gases in the container is determined as 9 atm.
What is total pressure of the gases?
The total pressure of the gasses is equal to the total pressure of the container.
Pt = P1 + P2 + P3
Pt = 1 atm (neon) + 2 atm (Argon) + 6 atm( xenon)
Pt = 9 atm
Thus, the total pressure of the mixture of the nobles gases in the container is determined as 9 atm.
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A/an _______ is the smallest unit of matter that has the characteristics of a chemical element. Question 9 options: A) proton B) atom C) molecule D) electron
Answer: atom
Explanation: molecule is a group or two or more atoms
protons and electron are subatomic particles
atom is the smallest unit of matter
Arrhenius theorized that an acid is a chemical compound that
Answer:
increases the H + ion concentration in aqueous solution
Explanation:
An Arrhenius base is a compound that increases the OH − ion concentration in aqueous solution. Arrhenius theory, theory, introduced in 1887 by the Swedish scientist Svante Arrhenius, that acids are substances that dissociate in water to yield electrically charged atoms or molecules, called ions, one of which is a hydrogen ion (H+), and that bases ionize in water to yield hydroxide ions (OH−). Arrhenius Definition of acids. An acid is a substance that dissociates in water to produce H+ (hydrogen ions) Arrhenius Definition of strong acids. A strong acid is a substance that fully dissociates in water to give hydrogen ions. Arrhenius Definition of weak acids.
When a chemical cold pack is activated, it becomes cool to the touch. What is happening in terms of energy?.
Answer:
An exothermic reaction is happening, it is absorbing the cold.
for now pliss help me
Answer:
the nucleoid
Explanation:
Complete the sentence using the word refracting, radlo, or space.
Telescopes that use lenses to bend light are called
telescopes.
Answer:
Refracting
Explanation:
Mark the word bend lightHence light travels through one medium to another it bends down which is called refraction.The bendness depends upon the refractive index of medium.Please Hurry And Answer This Question! :)
Which Compound can be used to preserve biological specimens?
1/2/3?
Biological specimens are the preserved remains of the biological materials. Compound A. formaldehyde or formalin is used to preserve the specimens. Thus, option A is correct.
What are fluid-preserved specimens?Fluid preserved specimens are the biological material of the organism that are kept at the store to study and analyze over a long time without getting any damage. Formaldehyde along with alcohol is the most common preservative.
Formaldehyde is an organic compound that is colorless and pungent in the smell that preserves the dead remains of the organisms intact. It is antiseptic and germicide in nature that makes them best for the purpose.
Therefore, option A. formaldehyde is used to preserve the specimens.
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Answer:
so i put a...
Explanation:
Edge doesnt give correct answers on unit tests, but i passed with an 88 :)
Correct me if im wrong!!