Unit 1: Intro to Chemistry

Atomic Structure

100

Which subatomic particle has a positive charge?
A. Electron
B. Neutron
C. Proton
D. Positron

C. Proton

200

Where are electrons found in an atom?
A. Nucleus
B. Electron cloud
C. Inner core
D. Proton shell

B - Electron Cloud

300

What does the atomic number represent?
A. Protons + neutrons
B. Electrons + neutrons
C. Number of neutrons
D. Number of protons

A - Protons + Neutrons

400

Which particle contributes the MOST to an atom’s mass?
A. Electrons
B. Protons and neutrons
C. Only electrons
D. Only protons

B. Protons and neutrons

500

Where does the mass number of an atom come from?
A. Protons only
B. Neutrons only
C. Protons + neutrons
D. Electrons + protons

C. Protons + neutrons

Isotopes

100

What makes isotopes of the same element different?
A. Number of protons
B. Number of neutrons
C. Number of electrons
D. Number of energy levels

B. Number of neutrons

200

All isotopes of an element have the same number of:
A. Neutrons
B. Electrons
C. Protons
D. Mass

C. Protons

300

A heavier isotope of an element has:
A. Fewer neutrons
B. More neutrons
C. More electrons
D. Fewer protons

B. More neutrons

400

Changing the number of neutrons changes an atom’s:
A. Identity
B. Charge
C. Mass
D. Group number

C. Mass

500

The average atomic mass on the periodic table is:
A. The mass of the most common isotope
B. A weighted average of all isotopes
C. The mass of the lightest isotope
D. Protons + electrons

B. A weighted average of all isotopes

Ions

100

What is an ion?
A. A neutral atom
B. An atom that gained or lost electrons
C. A molecule with covalent bonds
D. An atom that changed protons

B. An atom that gained or lost electrons

200

What do metals tend to do with electrons?
A. Gain electrons
B. Share electrons
C. Lose electrons
D. Split electrons

C. Lose electrons

300

A negative ion (anion) is formed when an atom:
A. Loses electrons
B. Gains electrons
C. Loses protons
D. Gains neutrons

B. Gains electrons

400

What type of ion forms when electrons are lost?
A. Anion
B. Cation
C. Noble ion
D. Isotope

B. Cation

500

Ionic bonds form when ions:
A. Repel each other
B. Share electrons
C. Attract each other
D. Change protons

C. Attract each other

Electron Configurations

100

According to the Aufbau Principle, electrons fill:
A. Highest energy orbitals first
B. Any orbital at random
C. Lowest energy orbitals first
D. Only the s orbital

C. Lowest energy orbitals first

200

Hund’s Rule states that electrons fill orbitals:
A. In pairs first
B. Singly before pairing
C. Only with opposite spins
D. Only in the s sublevel

B. Singly before pairing

300

How many electrons can the p sublevel hold?
A. 2
B. 6
C. 10
D. 14

B. 6

400

What is the electron configuration of oxygen?
A. 1s² 2s¹ 2p⁵
B. 1s² 2s² 2p⁴
C. 1s¹ 2s² 2p⁵
D. 1s² 2s² 2p⁶

B. 1s² 2s² 2p⁴

500

Which rule states that electrons in the same orbital must spin in opposite directions?
A. Hund’s Rule
B. Aufbau Principle
C. Pauli Exclusion Principle
D. Octet Rule

C. Pauli Exclusion Principle

The Periodic Table

100

What determines the arrangement of elements on the periodic table?
A. Mass number
B. Atomic mass
C. Atomic number
D. Number of neutrons

C. Atomic number

200

Elements in the same group have the same number of:
A. Neutrons
B. Protons
C. Electrons
D. Valence electrons

D. Valence electrons

300

Where are metals located on the periodic table?
A. Right side
B. Left side
C. Along the staircase
D. Only in the middle

B. Left side

400

Which group contains the most reactive metals? (Hint: because they only have ONE valence electron)
A. Halogens
B. Alkaline earth metals
C. Alkali metals
D. Noble gases

C. Alkali metals

500

Noble gases are stable because:
A. They have high mass
B. Their outer shells are full
C. Their neutrons are balanced
D. They have no electrons

B. Their outer shells are full