Do Now - Average Atomic Mass

What do these isotopes of carbon all have in common?

• neutrons & mass number

• protons and neutrons

• atomic number and average atomic mass

• protons and atomic number

Chlorine has two naturally occurring isotopes, Chlorine-35 and Chlorine-37, the atomic mass of chlorine is 35.45. Which of these two isotopes of chlorine is more abundant?

• ³⁵Cl

• ³⁷Cl

• Cannot be determined from the information provided.

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

which atom has  4 neutrons?

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

Tags

NGSS.MS-PS1-1

How many neutrons does the isotope of lithium have?

• 8
• 3
• 4
• 5

Tags

NGSS.HS-PS1-8

Which isotope of oxygen has 8 neutrons?

• O-16

• O-17

• O-18

• O-19

If an element has isotopes with masses of 10 amu and 11 amu, and the average atomic mass is 10.8 amu, which isotope is more abundant?

• 10 amu

• 11 amu

• Both are equally abundant

• Cannot be determined

Four isotopes of lead include lead-204, lead-207, and lead-208. The average atomic mass of lead is 207.2. Rank the isotopes in terms of predicted abundance.

• 204

• 208

• 207

Calculate the average atomic mass of this element.

• 106.38649amu
• 111.91896amu
• 107.8677amu
• 121

Tags

NGSS.HS-PS1-7

4.35% of all X atoms have a mass of 39.946 amu. 83.79% have a mass of 41.941 amu, 9.50% have a mass of 42.941 amu, and 2.36% have a mass of 43.939 amu. What is the average atomic mass of atom X?

• 42.00 amu

• 42.19 amu
• 10.43 amu
• 40.04 amu