Answer:
C. 14
Explanation:
The mass number is the number of protons + neutrons and the atomic number is the number of protons.
If the mass number is 27, you subtract the atomic number, 13.
27 - 13 = 14 neutrons
The answer is the plague, or the black death
PbO2
You have to take the mass of lead in the problem, and divide by the molar mass.
When you do the same with oxygen, you get a number about twice as large as when you divide the mass of lead by the molar mass of lead. This means that the simplest formula would be PbO2
Answer: 401.4g
Explanation:
The mass can be calculated by using the following mathematical expression for Moles ,which is:
Moles = Mass / Molar Mass
From the question given, Moles = 1.72, Molar mass of BaSO4 = 233.38g/mol, Mass =?
Making 'Mass' the subject of formula, we get:
Mass = Molar mass x Moles
= 233.38 x 1.72 = 401.4g
