Chemistry Test

How many neutrons does this isotope of lithium have?

• 8
• 3
• 4
• 5

How many protons does this isotope of titanium have?

• 70
• 26
• 22
• 48

The element copper has naturally occurring isotopes with mass numbers of 62.93 and 64.93.

The relative abundance and atomic masses are 69.2% for mass = 62.93 amu, and 30.8% for mass = 64.93 amu.

Calculate the average atomic mass of copper.

• 63.5 amu

• 62.93 amu

• 64.93 amu

• 63.93 amu

Calculate the atomic mass of bromine.

The two isotopes of bromine have atomic masses and relative abundance of 78.92 amu (50.69%) and 80.92 amu (49.31 %).

• 79 amu

• 81 amu

• 79.92 amu

• 79.91 amu

Which of the following are elements?

Separate your answers using a comma.

Which of the following are compounds?

Separate your answers using a comma.

Which of the following is a mixture?

Separate your answers using a comma.

12 protons and 13 neutrons

• Mg-12
• Mg-13
• Mg-25
• Mg-24

State the number of protons, neutrons, and electrons in this pair of isotopes.

Li–7 and Li–6

Write the numbers only.

State the number of protons, neutrons, and electrons in this pair of isotopes.

Ca–44 and Ca–42

Write the numbers only.