Chem Review Semester 1

In the picture, what is the Mass number?

• 19
• K
• 39.098
• potassium

Tags

NGSS.MS-PS1-1

Of the reactions below, which one is a decomposition reaction?

• NH₄ → NH₃ + HCl

• 2Mg + O → 2MgO

• 2N₂ + 3H₂ → 2NH₃

• 2CH₄ + 4O₂ → 2CO₂ + 4H₂O

How many elements are represented in the compound, Na₂CO₃ ?

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-1

Which of the following are examples of elements?

• NaCl, O, CO2
• C, Au, Ag, Al
• Hg, Al, LiF
• Salt, Water, Steel

How many protons does this element have?

• 40
• 21
• 20
• 41

Tags

NGSS.MS-PS1-1

How many neutrons does this element have?

• 11
• 23
• 22
• 12

Tags

NGSS.MS-PS1-1

How many chlorine atoms are in a molecule of Ba(ClO₄)₂?

• 1

• 2

• 4

• 8

Tags

NGSS.MS-PS1-1

Which of the following has 5 valance electrons?

• boron

• carbon

• nitrogen

• oxygen

• fluorine

What is the charge of a calcium ion?

• +1

• +2

• +/-4

• -1

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

• MgI₂

• MgI

• Mg₂I

• Mg₂I₂

Tags

NGSS.MS-PS1-1