Isotopes and Calculating Atomic Mass

In order for two elements to be isotopes, what has to be the SAME?

• Protons

• Electrons

• Neutrons

• Mass

In order for two elements to be isotopes, what must be DIFFERENT?

• Protons

• Electrons

• Neutrons

• Neutrons & Mass

Tags

NGSS.HS-PS1-8

Which isotope of Lithium contains 4 neutrons?

• Li-6

• Li-7

• Li-8

• They have the same # of neutrons

Tags

NGSS.MS-PS1-1

Looking at the following mass spectrum of neon, how many isotopes does neon have?

• 1

• 2

• 3

• 4

Looking at the following mass spectrum of neon, which isotope is most abundant?

• Ne-20

• Ne-21

• Ne-22

Nitrogen has two isotopes. One isotope has a mass of 14.003 amu and a relative abundance of 99.63%, while the other has a mass of 15.000 amu and a relative abundance of 0.37%. What is the average atomic mass for nitrogen?

• 14.993 amu

• 14.456 amu

• 14.778 amu

• 14.007 amu

Calculate the atomic mass of silicon. The three silicon isotopes have atomic masses and relative abundances of 27.9 amu (92.2%), 28.9 amu (4.7%) and 29.9 amu (3.1%). Round your answer to 3 sig figs and only type a #.

Calculate the average atomic mass of the following element:

²⁵Y (11%), ³²Y (39%), ²⁹Y (22%), ³⁰Y (28%)

• 32.0

• 30.0

• 29.0

What do all isotopes of hydrogen have in common?

• 1 proton

• 1 electron

• Mass of 1

• 1 neutron

If an atom has a mass of 40 amu and an atomic # of 19, what else do you know?

• 19 protons

• 20 neutrons

• 21 neutrons

• 19 neutrons

Tags

NGSS.MS-PS1-1