Answer: A. Limestone rocks dissolving in water
Explanation:
B: This is a physical change; it changes an object physically rather than chemically. It does not change the composition of the concrete, only the shape.
C: This is also a physical change because the water is just dragging sand with it, but not actually changing the composition of it.
D: Similar to option B, this is an example of physical weathering because the ice only divides the rock into different parts but doesn't change the composition or complexity of it.
Answer is: 79.8 grams of copper(II) sulfate.
N(CuSO₄) = 3.01·10²³; number of molecules.
n(CuSO₄) = N(CuSO₄) ÷ Na.
n(CuSO₄) = 3.01·10²³ ÷ 6.02·10²³ 1/mol.
n(CuSO₄) = 0.5 mol; amount of substance.
m(CuSO₄) = n(CuSO₄) · M(CuSO₄).
m(CuSO₄) = 0.5 mol · 159.6 g/mol.
m(CuSO₄) = 79.8 g; mass of substance.
M - molar mass.
Explanation:
It is often desirable to determine the mass percent of elements in a given compound.
To determine the mass percent of elements:
- Evaluate the formula mass of the compound. This is done by summing the atomic masses of the atoms in the compound together.
- The mass percentage is determined by pacing the mass contribution of each element or group to the formula mass of the compound and multiply by 100.
Learn more:
Percent by mass brainly.com/question/5544078
#learnwithBrainly
The number of electrons when the quantum number n=2 is 8 electrons. Variab<span>le </span>n<span> represents the principal quantum number which is the number of the energy level. </span>
Answer:
978mmHg
Explanation:
The total pressure of a gas mixture is defined as the sum of the pressure of each gas in the mixture.
If the mixture of gases you have 200mmHg for O₂, 350mmHg for N₂ and 428mmHg for He, total pressure of the mixture is:
200mmHg + 350mmHg + 428mmHg = <em>978mmHg</em>
