Chapter 3 Chem

What is the atomic number?

• the number of protons in the nucleus

• the number of protons and neutrons in the nucleus

• the number of neutrons in the nucleus

• the number of protons in the energy levels

What is the mass number?

• the number of protons in the nucleus

• the number of protons and neutrons in the nucleus

• the number of neutrons in the nucleus

• the number of protons and electrons in the atom

Most of the mass in an atom is made up of _____________________?

• protons and electrons
• protons and neutrons
• neutrons and electrons
• electrons and quarks

In order for an atom to be neutral what has to be true?

• The atom has more protons than neutrons
• The atom has more neutrons than protons
• The atom has the same number of protons and neutrons
• The atom has the same number of protons and electrons

What does the C represent?

• atomic mass
• atomic number
• element name
• chemical symbol 

What does the 6 represent?

• Atomic mass

• atomic number

• chemical symbol

• element name

How is the number of neutrons in the nucleus of an atom calculated?

• Add the number of e- and p+ together
• Subtract the number of e- from p+
• Subtract the number of p+ from the mass number
• Add the mass number to the number of e-

If an atom has 12 positively charged subatomic particles, which of the following must it also have to be considered a neutral atom?

• 12 neutrons
• 12 electrons
• 12 protons
• 24 protons and neutrons

An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.

• 20

• 10

• 35

• 25

The atomic number of an element that has 9 protons, 9 electrons, and 10 neutrons is _____.

• 9
• 10
• 19
• 28