Understanding Atomic Structure and Ions

The video is an exam review for a Grade 8 chemistry midterm, covering topics such as atoms, metals and nonmetals, molecules, and ions. It includes exercises on identifying elements in the periodic table, determining electronic configurations, calculating atomic numbers and mass, and understanding ion charges. The video also explains the structure of oxygen atoms and ions, and how to write molecular formulas and classify molecules.

Which of the following topics is NOT covered in the midterm exam?

• Metals and Nonmetals

• Chemical Reactions

• Atoms

• Ions

What is the electronic configuration of lithium?

• K2 L2

• K1 L2

• K1 L1

• K2 L1

How many shells does aluminium have in its electronic configuration?

• Four

• Three

• Two

• One

What is the atomic number of carbon if it has 6 neutrons?

• 14

• 8

• 12

• 6

What is the charge of a nitride ion after gaining three electrons?

• -2

• -3

• 0

• -1

Why is diagram B considered an ion in the oxygen atom structure?

• Equal neutrons and electrons

• More electrons than protons

• More protons than electrons

• Equal protons and electrons

What is the chemical symbol for an oxide ion with a charge of -2?

• O3-

• O2-

• O-

• O2

Which of the following is a compound?

• H2

• C2H4

• N2

• O2

What is the atomicity of ammonia (NH3)?

• 5

• 2

• 3

• 4

How many carbon atoms are present in three molecules of ethylene (C2H4)?

• 6

• 2

• 4

• 8