Average atomic mass

How can you determine the relative atomic mass of an atom?

• add protons, neutrons, and electrons

• add protons and neutrons

• subtract mass number and protons

• add protons and electrons

Tags

NGSS.HS-PS1-7

Four isotopes of lead include lead-204, lead-206, lead-207, and lead-208.  The average atomic mass of lead is 207.2.  Which isotope of lead is likely to be the most abundant.

• 204
• 206
• 207
• 208

Tags

NGSS.MS-PS1-1

The masses of atoms are generally given in what units?

• grams

• atomic mass units

• moles

• micrograms

The most common isotope of oxygen is ___.

• oxygen-16

• oxygen-8

• oxygen-15

• oxygen-18

Tags

NGSS.MS-PS1-1

What is the average atomic mass of silver?

• 108 g

• 107 amu

• 107.8682 amu

• 107.9692 g

The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is __________ amu.

• 219.7

• 220.4

• 221.0

• 218.5

An unidentified element has two naturally occurring isotopes. One has an atomic mass of 78.92 amu and a natural abundance of 50.69%. The other has a mass of 80.92 amu and a natural abundance of 49.31%. What is the identity of the element?

• bromine

• krypton

• boron

• arsenic

Tags

NGSS.HS-PS1-1

Mass spec images look like the one shown below. Use the image to determine the number of isotopes of uranium

• 3

• 5

• 2

• 234

Tags

NGSS.HS-PS1-8

A mystery element has three naturally occurring isotopes. 95% of these isotopes have an atomic mass of 31.972 amu. 4.22% of isotopes have an atomic mass of 33.967 amu, and 0.76% have an atomic mass of 32.971 amu. What is the element?

• phosphorus

• gallium

• sulfur

• chlorine

Tags

NGSS.HS-PS1-8

What is the relative atomic mass of an isotope that contains 10 protons, 12 neutrons, and 10 electrons?

• 32 amu

• 22 grams

• 32 grams

• 22 amu