Chemical Equations

Which of the following is evidence that a chemical change has taken place? 

• change in color
• change in size
• change in shape
• change in energy

How many oxygen atoms are present in the following? 
4Ca(OH)₂

• 4
• 6
• 8
• 1

Tags

NGSS.MS-PS1-1

Why must we balance chemical equations? 

• Our teacher said so
• to abide by the law of conservation of energy
• to abide by the law of conservation of mass

Tags

NGSS.MS-PS1-5

How many E atoms are there in this silly formula?
2E₂Fg₃Hi₄

• 4
• 2
• 1
• 3

Tags

NGSS.MS-PS1-5

Which of the following can be broken apart in a chemical reaction? 

• Noble gases
• Molecules and compounds
• only molecules
• only compounds 

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

 Fill in the blank to balance the chemical equation. 
2KI  +  ____Cl₂ →  2KCl  +  I₂

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-5

What coefficient should go in the blank space to balance the chemical equation?

2Al +____ HCl → 2AlCl₃ + 3H₂

• 2

• 4

• 3

• 6

Which is the Law of Conservation of Matter?

• matter cannot be created or destroyed, it only changes form
• matter can be created but it cannot be destroyed, it never changes form
• matter can be destroyed but it cannot be created, it usually just changes form
• matter is an unproven theory created by Hans Geiger

Tags

NGSS.MS-PS1-5