Chemical formulas practice

What is the correct formula for the ionic compound formed between sodium and chlorine?

• NaCl

• Na2Cl

• NaCl2

• Na2Cl3

Answer explanation

The correct formula for the ionic compound formed between sodium (Na) and chlorine (Cl) is NaCl. Sodium has a +1 charge and chlorine has a -1 charge, resulting in a 1:1 ratio, hence NaCl is the correct choice.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following represents a correct binary ionic compound?

• K2O

• CO2

• MgCl

• H2S2

Answer explanation

K2O is a correct binary ionic compound, consisting of potassium (K) and oxygen (O) ions. The other options either contain covalent bonds (CO2, H2S2) or are not properly formed ionic compounds (MgCl).

Tags

NGSS.HS-PS1-2

What is the formula for the compound formed between aluminum and oxygen?

• AlO2

• Al2O

• Al2O3

• AlO3

Answer explanation

The correct formula for the compound formed between aluminum and oxygen is Al2O3. Aluminum has a +3 charge and oxygen has a -2 charge, requiring two aluminum ions to balance three oxide ions, resulting in Al2O3.

Tags

NGSS.HS-PS1-2

Which pair represents a correct binary ionic compound?

• CaF2

• CO

• Na2O2

• KClO

Answer explanation

CaF2 is a correct binary ionic compound, consisting of calcium (Ca) and fluoride (F) ions. The other options either contain covalent bonds (CO) or are not simple binary ionic compounds (Na2O2, KClO).

Tags

NGSS.HS-PS1-2

What is the correct formula for the ionic compound formed between magnesium and bromine?

• MgBr

• MgBr2

• Mg2Br

• Mg2Br3

Answer explanation

The correct formula for the ionic compound formed between magnesium (Mg) and bromine (Br) is MgBr2. Magnesium has a +2 charge and bromine has a -1 charge, requiring two bromine ions to balance the charge.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following is a correct binary ionic compound?

• Na2S

• NaNO3

• Al2(SO4)3

• CaCO3

Answer explanation

Na2S is a binary ionic compound consisting of sodium (Na+) and sulfide (S2-) ions. The other options contain polyatomic ions or are not purely ionic, making Na2S the correct choice.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the correct formula for the ionic compound formed between potassium and sulfur?

• K2S

• KS2

• K2SO4

• KSO4

Answer explanation

The correct formula for the ionic compound formed between potassium (K) and sulfur (S) is K2S. Potassium has a +1 charge and sulfur has a -2 charge, requiring two potassium ions to balance one sulfur ion.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which pair represents a correct binary ionic compound?

• Ba(ClO3)2

• NO3

• Li2SO4

• BeF2

Answer explanation

BeF2 is a correct binary ionic compound, consisting of beryllium (Be) and fluorine (F) ions. The other options either contain polyatomic ions or are not binary ionic compounds.

Tags

NGSS.HS-PS1-2

What is the formula for the compound formed between calcium and nitrogen?

• CaN

• Ca2N

• Ca3N2

• Ca2N3

Answer explanation

The formula for the compound formed between calcium (Ca) and nitrogen (N) is Ca3N2. Calcium has a +2 charge and nitrogen has a -3 charge, requiring three calcium ions to balance two nitride ions, resulting in Ca3N2.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following is a correct polyatomic ionic compound?

• CO

• Na2CO

• Mg(NO3)2

• KBr

Answer explanation

Mg(NO3)2 is a correct polyatomic ionic compound, consisting of magnesium ions and nitrate ions. The other options either lack polyatomic ions or are not ionic compounds.