LE Unit 2 Study Guide: Atoms to Molecules

What does the atomic number of an element represent?

• Number of electrons

• Number of neutrons

• Number of protons

• Total number of nucleons

What happens when the number of protons in an atom changes?

• It becomes an isotope

• It becomes a different element

• It gains or loses an electron

• It remains the same element

What are isotopes?

• Atoms with different numbers of protons

• Atoms with different numbers of neutrons

• Atoms with different numbers of electrons

• Atoms that are ions

An atom that loses an electron becomes a:

• Neutral atom

• Positively charged ion

• Negatively charged ion

• Molecule

The outermost electrons in an atom determine its:

• Atomic mass

• Atomic number

• Chemical properties

• Isotope form

Changing the number of which particle would change an atom into an ion?

• Proton

• Neutron

• Electron

• Nucleon

Which subatomic particle has a neutral charge?

• Proton

• Neutron

• Electron

• Ion

What is the significance of valence electrons in chemical reactions?

• They determine how atoms bond with each other

• They determine the atomic mass

• They are only present in metals

• They are the same as free radicals

In the atomic nucleus, you would find:

• Electrons and protons

• Protons and ions

• Protons and neutrons

• Neutrons and electrons

A neutral atom has the same number of:

• Protons and neutrons

• Protons and electrons

• Electrons and neutrons

• Isotopes and ions