A
The number of electrons/protons is the one that determines the atomic number of an element.
Answer:
D. Sweat evaporates from your skin
Explanation:
A physical change is a reversible process, no new substance is formed. A physical change does not affect the chemical composition of a substance.
Sweat evaporation from the skin is a physical change, because the change that occur is merely a change of state, Liquid to Gaseous state, no new substance is formed.
Answer:
the mass of 2.9 moles of calcium is 116 g
Explanation:
The computation of the mass of 2.9 moles of calcium is shown below
As we know that
Mole = mass ÷ molar mass
where,
Moles be 2.9
And, we know that the molar mass of calcium be 40g/mol
Now put the values to the above formula
2.9 = Mass ÷ 40
So, the mass would be
= 40 × 2.9
= 116 g
Hence, the mass of 2.9 moles of calcium is 116 g
Answer: 51.9961 g/mol, don't know if it helps :)
Explanation: