STAAR Review - The Atom

Based on the numbers of subatomic particles, which of the following atoms will have a positive charge?

• Protons=6, Neutrons=6, Electrons =6
• Protons=7, Neutrons=6, Electrons =6
• Protons=9, Neutrons=10, Electrons =9
• Protons=10, Neutrons=11, Electrons =11

A table with information about four elements is provided. Which element contains 22 protons?

• Sodium
• Calcium
• Titanium
• Magnesium

The reactivity of an element is most greatly influenced by which of the following?

• Number of valence electrons
• Melting point
• Numbers of protons
• Atomic mass

Which of the following correctly describes a proton?

• Location: nucleus, Contribution to mass: usually about half, Charge: positive
• Location: nucleus, Contribution to mass: virtually none, Charge: positive
• Location: outside nucleus, Contribution to mass: usually about half, Charge: positive
• Location: nucleus, Contribution to mass: usually about half, Charge: none

An atom of an element has 12 protons. How many electrons does the atom have if it has a charge of positive 2 (+2)?

• 2
• 10
• 14
• 24