U2Q2: The Atom

Front

What is the average atomic mass of an element with isotopes of 75.23 amu (24.1%), 74.61 amu (48.7%), and 75.20 amu (27.2%)?

Back

74.92 amu

Front

How many neutrons does the isotope of lithium (Li) with mass number 8 have?

Back

3 neutrons

Front

An atom has an atomic number of 19 and a mass number of 29. How many neutrons does it have?

Back

10 neutrons

Front

What is the charge of an atom that has more electrons than protons?

Back

It is an ion and negatively charged.

Front

What does it mean if an atom has a +3 charge?

Back

It has lost 3 electrons.

Front

Define atomic number.

Back

The number of protons in the nucleus of an atom, which determines the element's identity.

Front

Define mass number.

Back

The total number of protons and neutrons in an atom's nucleus.

Front

What is an isotope?

Back

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Front

What is the relationship between protons, neutrons, and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

How do you calculate the average atomic mass of an element?

Back

Multiply the mass of each isotope by its relative abundance (as a decimal), then sum the results.