7th grade 2.17.20

True or False
In a chemical reaction, no new atoms are created, and no atoms are destroyed. 

• true
• false

Tags

NGSS.MS-PS1-5

A chemical change is different than a physical change because in a chemical change

• Chemicals are used
• Molecules do not physically touch
• A new substance is formed and in a physical change no new substance is formed
• The change can be seen but in a physical change it cannot

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

The left side of the equation below is called

• Products
• Reactants

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-1

The right side of the equation below is called the

• products
• reactants

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Is this balanced?...
Al + O₂ --> 2Al₂O₃

• Yes!
• NO!

Tags

NGSS.MS-PS1-5

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled
• the product is half the mass of the reactants
• the mass is the same
• the mass changes depending on the reaction

Tags

NGSS.MS-PS1-5

Why is the following chemical equation not balanced?
H_{2 +} O₂ --> H₂O

• each side of the equation has a different number of oxygen atoms
• each side of the equation has a different number of hydrogen atoms
• each side has the same mass

Tags

NGSS.MS-PS1-5

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂ --> 2Al₂ O₃

• 2
• 6
• 1
• 4

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Why is the following chemical equation not balanced?
H_{2 +} O₂ --> H₂O

• each side of the equation has a different number of oxygen atoms
• each side of the equation has a different number of hydrogen atoms
• each side has the same mass

Is the following equation balanced or unbalanced?
Fe + S --> FeS

• balanced
• unbalanced

Tags

NGSS.MS-PS1-5