Chemical reactions

When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic?

• a change of color
• a change of state
• a temperature decrease
• a temperature increase

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS3-4

What types of reactions absorb and release heat?

• acidic and basic
• endothermic and exothermic
• endothermic and heat transfusion
• covalent and ionic

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-3

Which of the following is a chemical change?

• water freezes to form ice
• sugar dissolves in water
• gasoline burns in a car engine
• a piece of metal expands when it is heated

Tags

NGSS.MS-PS1-2

In the reaction methane + oxygen turns into carbon dioxide + water, the methane and oxygen are called _______________.

• reactants
• products
• neutrals
• energizers

A change in the shape of an object is an example of _________________.

• a chemical change
• energy
• an endothermic change
• a physical change

What type of change occurs when a new substance is formed that has different properties from the original substances?

• chemical change
• nuclear change
• physical change
• mutation

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Which of the following is an example of a physical change?

• souring milk
• mixing baking soda and vinegar
• rusting metal
• mixing oil and vinegar

Tags

NGSS.MS-PS1-4

Which of the following is a chemical change?

• the rusting of iron
• dissolving salt in water
• melting an ice cube
• bending a copper wire

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

In any chemical reaction, the mass of the products is always:

• slightly less than the mass of the reactants
• much less than the mass of the reactants
• the same as the mass of the reactants
• greater than the mass of the reactants

Tags

NGSS.MS-PS1-5

the starting materials in a chemical reaction

• Products
• Reactants
• Starters
• Enders

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2