Chemistry Final Practice

What is the atomic number?

• the number of protons
• the number of protons and neutrons
• the number of neutrons
• the number of protons and electrons

What is the mass number defined as?

• the number of protons
• the number of protons and neutrons
• the number of neutrons
• the number of protons and electrons

What is the atomic number of this atom?

• 1
• 3
• 4
• 7

What is the mass number of this atom?

• 1

• 3

• 4

• 7

Atoms of the same element which have a different number of neutrons are called _________________.

• ions

• isotopes

• quarks

• molecules

The average atomic mass of an element is the ___.

• average of the mass number and the atomic number for the element

• average of the masses of the isotopes of the element

• total mass of the isotopes of the element

• total number of subatomic particles in the nucleus

which atom has  4 neutrons?

• Li-6
• Li-7
• Li-8
• they have the same # of neutrons

How many electrons are in an neutral atom with an atomic number of 50?

• 5

• 8

• 50

• 2

The number of significant figures in: 405,000

• 6

• 5

• 4

• 3

The number of significant figures is: 0.00008770

• 8

• 4

• 3

• 7