Answer:
The protons and electrons in each element are equal. The sulfur has 16 electrons and 16 protons. But the ionic atom's electron quantity changes depending on how many it has gained. 'S2-' has gained 2 electrons, which means it has now 18 electrons and 16 protons. 16 neutrons
Explanation:
Which of the following is a radioactive element?Sodium, Fluorine,Oxygen
francium
Answer:
Fluorine
Explanation:
These particles stick in the atoms and make them radioactive.
The compound sodium nitrate is a strong electrolyte. Write the transformation that occurs when solid sodium nitrate dissolves in water.
Answer and Explanation:
Since the compound sodium nitrate (NaNO₃) is a strong electrolyte, it dissociates completely into ions when is dissolved in water, as follows:
NaNO₃(s) → Na⁺(aq) + NO₃⁻(aq)
So, the solid compound produces the sodium cation (Na⁺) and the nitrate anion (NO₃-) in the aqueous medium.
Measurements show that unknown compound X has the following composition: element mass % chromium 68.4% oxygen 31.5% Write the empirical chemical formula of X.
Answer: The empirical formula of X is [tex]Cr_2O_3[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of Cr = 68.4 g
Mass of O = 31.5 g
Step 1 : convert given masses into moles.
Moles of Cr =[tex]\frac{\text{ given mass of Cr}}{\text{ molar mass of Cr}}= \frac{68.4g}{52g/mole}=1.31moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{31.5g}{16g/mole}=1.97moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Cr = [tex]\frac{1.31}{1.31}=1[/tex]
For O = [tex]\frac{1.97}{1.31}=1.5[/tex]
The simple whole number ratio of Cr : O= 2: 3
Hence the empirical formula is [tex]Cr_2O_3[/tex]
A solution is made by mixing 49.g of chloroform CHCl3 and 73.g of acetyl bromide CH3COBr. Calculate the mole fraction of chloroform in this solution. Round your answer to 2 significant digits.
Answer: The mole fraction of chloroform in this solution is 0.41
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
a) moles of [tex]CHCl_3[/tex]
[tex]\text{Number of moles}=\frac{49g}{119g/mol}=0.41moles[/tex]
b) moles of [tex]CH_3COBr[/tex]
[tex]\text{Number of moles}=\frac{73g}{123g/mol}=0.59moles[/tex]
To calculate the mole fraction, we use the formula:
[tex]\text{Mole fraction of a component}=\frac{\text{Moles of the component}}{\text{total moles}}[/tex]
[tex]\text{Mole fraction of chloroform}=\frac{\text{Moles of chloroform}}{\text{total moles}}=\frac{0.41}{0.41+0.59}=0.41[/tex]
The mole fraction of chloroform in this solution is 0.41
What is the difference between an atomic symbol and a chemical symbol?
Answer: A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
What do you think the saying ‘think globally, act locally’ means? How does this apply to the issue of plastic debris in the ocean?
A mixture of ethyne gas (C2H2) and methane gas (CH4) occupied a certain volume at a total pressure of 16.8 kPa. When the sample burned, the products were CO2 gas and H2O vapor. The CO2 was collected and its pressure found to be 25.2 kPa in the same volume and at the same temperature as the original mixture. What percentage of the original mixture was methane
Answer:
50%
Explanation:
Let assume that there are:
"a" moles of CH4 & "b" moles of C2H2
Then by applying the ideal gas equation:
PV = nRT
[tex]16.8 \times 10^3 \times V = (a+b)RT[/tex]
Make (a+b) the subject of the formula:
[tex](a+b) = \dfrac{16800 \ V }{RT} mol[/tex] --- (1)
Since 1 mole of CH₄ yields 1 mol of CO₂ & 1 mol of C₂H₂ yields 2 moles of CO₂
Then;
the total moles of CO₂ = (a +2b)
Now:
[tex]25.3 \times 10^3 \times V = (a+ 2b)RT[/tex]
[tex](a + 2b) = \dfrac{25200 \ V}{RT \ mol}[/tex] ---- (2)
∴
By solving the above equations
[tex]a = \dfrac{8400 \ V}{RT} \\ \\ b = \dfrac{8400 \ V}{RT}[/tex]
Hence, the estimate of the percentage of methane in the original mixture is:
[tex]= 100 \times \dfrac{a}{(a+b)}[/tex]
[tex]= 100 \times \dfrac{8400\dfrac{ \ V}{RT} }{8400\dfrac{ \ V}{RT} + 8400\dfrac{ \ V}{RT}}[/tex]
= 50%
A 2.26 M solution of KOH is prepared. Calculate the moles and mass of solute present in a 15.2-mL sample of this solution. The molar mass of KOH is 56.11 g/mol.
Answer:
0.0344 moles and 1.93g.
Explanation:
Molarity is defined as the ratio between moles of a solute (In this case, KOH), and the volume. With molarity and volume we can solve the moles of solute. With moles of solute we can find mass of the solute as follows:
Moles KOH:
15.2mL = 0.0152L * (2.26mol / L) = 0.0344moles
Mass KOH:
0.0344 moles * (56.11g/mol) = 1.93g of KOH
What should a student do to set a goal? Check all that apply.
Create a plan.
Make a schedule.
Schedule lots of tasks.
Rush into the goal.
Pace him or herself.
Answer:
create a plan
the ways of of a student to set a goal
1. Write clear and measurable goals
2.Create a specific plan for each goal
3.Read your goals daily and visualize yourself accomplishing them
4. Reflect yourself to see if you are on target
5. Revise your action plans if needed.
1.)make a plan
2.)make a schedule
5.)pace him or herself
11. Everybody loves Mr Brown
Answer:
NO I DON'T ✌✌✌✌✌✌✌✌✌
Identify the ionic compound that can form between potassium as the metal and nitrogen as the nonmetal.
help!!
Answer:
[tex]6K _{(s)} + N _{2(g)} = = > \:2K _{3} N _{(s)} [/tex]
Potassium nitride
Number of atoms in 4.5 moles of Au?
whats the Number of molecules in 1.500 mole of H2O
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.
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.
Mathematically,
number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)
number of moles =1.500 mole
substituting all the given values in the above equation, we get
number of atoms/molecules=1.500 × 6.022×10²³(Avogadro number)
number of atoms/molecules =9.033×10²³molecules
Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.
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(5) Use scientific notation, make the following conversions:
6.20 km to m
Answer:
6200 meters
Explanation:
To convert from km to m you have to multiply the number by a thousand
Answer:
6.2×10^3 m
Explanation:
6.20×1000=6200m
In scientific notation 6200 = 6.2×10^3
What is the molarity of a solution of 10% by mass cadmium sulfate, CdSO4 (molar mass = 208.46 g/mol) by mass? The density of the solution is 1.10 g/mL.
a. 0.528 M
b. 0.436 M
c. 0.479 M
d. 0.048 M
e. 22.9 M
Answer:
a. 0.528 M .
Explanation:
Hello!
In this case, since the given by-mass percent can be written as:
[tex]\frac{10gCdSO_4}{100g\ sol}[/tex]
By using the density and molar mass of the solute, cadmium sulfate, we can compute the molarity, by also making sure we convert from mL to L of solution:
[tex]M=\frac{10gCdSO_4}{100g\ sol}*\frac{1molCdSO_4}{208.46gCdSO_4} *\frac{1.10g\ sol}{1mL\ sol}*\frac{1000mL}{1L} \\\\ M=0.528M[/tex]
Thereby, the answer is a. 0.528 M .
Best regards.
The molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.
To calculate molarity we need to find out how many moles of CdSO4 are present in the solution.
Given:
Mass of [tex]CdSO_4[/tex]= 10% by mass of the solutionMolar mass of [tex]CdSO_4[/tex] = 208.46 g/molDensity of the solution = 1.10 g/mLWe need to calculate the mass of [tex]CdSO_4[/tex]:
Mass of [tex]CdSO_4[/tex] = (10% / 100%) * Total mass of the solution
Mass of [tex]CdSO_4[/tex] = (10 / 100) * 1000 g (since the volume is 1 L, and the density is 1.10 g/mL)
Mass of [tex]CdSO_4[/tex] = 100 g
So, the number of moles of CdSO4:
Number of moles of [tex]CdSO_4[/tex] = Mass of CdSO4 / Molar mass of CdSO4
Number of moles of [tex]CdSO_4[/tex] = 100 g / 208.46 g/mol
Number of moles of [tex]CdSO_4[/tex] ≈ 0.479 moles
Then, we calculate the molarity of the solution:
Molarity = Number of moles of CdSO4 / Volume of the solution (in liters)
Molarity = 0.479 moles / 1 L
Molarity ≈ 0.479 M
Hence, the molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.
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find the weight of HNO_3 present in 20ml, 0.30 N
Answer:
mass of HNO₃ = 0.378 g
Explanation:
Normality = Molarity * number of equivalents
Molarity = Normality/number of equivalents
normality of HNO₃ = 0.30 N, Volume = 20 mL
HNO₃ ionizes in the following way:
HNO₃(aq) ----> H⁺ + NO₃⁻
Therefore, number of equivalents for HNO₃ is 1
molarity of HNO₃ = 0.30/1 =0.30 mol/dm³
Using the formula, molarity = number of moles/volume in liters
number of moles = molarity * volume
Number of moles of HNO₃ = 0.30 mol/dm³ * 20ml * 1 dm³ /1000 mL
number of moles = 0.006 moles
From the formula, mass = number of moles * molar mass
molar mass of HNO₃ = 63.0 g/mol
mass = 0.006 * 63
mass of HNO₃ = 0.378 g
The weight of an object is different on each planet because
O mass changes with location
O each planet has a different force of gravity
O each planet is a different distance from the sun
Omass of the object changes on each planet
Answer:
each planet has a different force of gravity
Explanation:
Weight = mass× gravity
As gravity changes from place to place and also from planet to planet so weight changes.
30 POINTS HELP Which idea was supported by Aristarchus, Copernicus, and Galileo?
The planets have epicycles.
The planets revolve around the Sun.
The stars rotate around the Sun.
The center of the solar system is Earth.
Answer:
SO SORRY it took so long but the answer is B :)
Explanation:
Trust me and good luck :)
The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.
What is Aristarchus?Aristarchus of Samos was just a Greek astronomer that suggested the very first heliocentric model of the cosmos, wherein the sun, rather than the earth, was even at its center. Despite the fact that his hypothesis was acknowledged by other philosophers of the time, it was dismissed as unrealistic, and the geocentric model remained in use for the next 1,700 years.
What is Copernicus?Copernicus was also the first to assert that the Earth as well as the other planets orbit the sun. It was really a significant shift in thinking.
What is sun?Sun can be considered as a star in solar system.
The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.
Therefore, the correct answer will be option (b).
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What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n = 2?
Answer:
[tex]4.86\times10^{-7}\ \text{m}[/tex]
Explanation:
R = Rydberg constant = [tex]1.09677583\times 10^7\ \text{m}^{-1}[/tex]
[tex]n_1[/tex] = Principal quantum number of an energy level = 2
[tex]n_2[/tex] = Principal quantum number of an energy level for the atomic electron transition = 4
Wavelength is given by the Rydberg formula
[tex]\lambda^{-1}=R\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right)\\\Rightarrow \lambda^{-1}=1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\\\Rightarrow \lambda=\left(1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\right)^{-1}\\\Rightarrow \lambda=4.86\times10^{-7}\ \text{m}[/tex]
The wavelength of the light emitted is [tex]4.86\times10^{-7}\ \text{m}[/tex].
How does energy from Earth’s interior affect surface changes?
Answer:
Energy produced deep inside Earth heats rock in the mantle. ... As it becomes less dense, the heated rock rises toward Earth's surface. The cooler, denser rock surrounding the heated rock sinks, as Figure 5 shows. In this way, heat inside Earth moves toward the cooler crust.
Explanation:
do you like my og name
Energy from Earth’s interior affect surface changes due to:
Earth heat transport occurs by conduction, mantle convection, hydrothermal convection, and volcanic advection. Thus, about 99% of Earth's internal heat loss at the surface is by conduction through the crust, and mantle convection is the dominant control on heat transport from deep within the Earth.Tectonic processes and flow in Earth's interior drive deformation of Earth's surface that can lead to destructive earthquakes, tsunamis, and volcanic eruptions.Learn more:
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Name the similarities between a animal cell and a plant cell
Answer:
Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.
Explanation:
I hope it's help
What is the molar mass of magnesium sulfate, MgSO4?
Answer:
120.37 g/mol is the molar mass of magnesium sulfate
How would a long period without sunlight affect the food web? PLEZZ HELP MEH IF YOU WANT BRAINEIST AND LIKE COMMENTED
It would cause consumers to consume more food.
It would have no effect on the food web.
It would stop decomposers from breaking down matter.
It would stop producers from producing food.
Answer:
im pretty sure its the last one
Explanation:
if plants dont have sun light they will die because the sunlight gives them the nutrients to survive
What are 3 characteristics of all invertebrates
Answer:
None have backbones
No cell walls
Multicellular
Includes radial or bilateral body symmetry.
Explanation:
The modern form of the periodic table results in the _____ ,which states that when elements are
arranged according to increasing atomic number
Answer:
The periodic law states “When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties
Which equation could be used to solve for the average speed of a car that travels 90m in 20 seconds?
Answer:
Vav=d/t
Explanation:
Because the question already gave d=90m and t=20s. Because the car is the thing that can not travel the same distances at the same times.So the equation is V[tex]\\_{av}[/tex]=[tex]\frac{d}{t} \\[/tex]
Atoms are stationary and don't move when in solid form.
False
True
Answer:
True? The don't stay exactly still i dont think, but i'd say true.
Explanation:
Answer:
TRUE
Explanation:
In a solid, atoms are packed tightly together and move very slowly. In fact, they do not flow at all: they simply vibrate back and forth.
Key words vibrate, not movement.
Correct me if I'm wrong of course
How do we use positive and negative signs to communicate the direction of a vector
Answer:
Two vectors are equal if they have the same magnitude and the same direction. Just like scalars which can have positive or negative values, vectors can also be positive or negative. A negative vector is a vector which points in the direction opposite to the reference positive direction.
How many protons, neutrons, and electrons does Sr^2+
Answer:
36 electrons
Explanation:
The # of protons is always equal to the atomic number. In the case of Sr (Strontium), it is 38 protons.
The 2+ at the end means that it has a charge of +2, meaning that it LOST two electrons to become a cation with a full valence shell. So, 38 - 2 = 36 electrons
Answer:
38 protons 36 electrons 30 neutron because of 29 isotope
12. Which of these is a solution? *
Gold
Salt
Water
Carbonated Water
All of the above.
Answer:
carbonated water
remaining are single element
