The formation of a solid when two liquids combine is called?

• Solidification

• Precipitate

• Freezing

• Solubility

Tags

NGSS.MS-PS1-2

During photosynthesis, carbon dioxide and water combine according to the general equation:

Why is photosynthesis a chemical reaction?

• because new substances are formed

• because the reactants are compounds

• because an input of energy is required

• because the products include an element

Tags

NGSS.MS-LS1-6

NGSS.MS-PS1-5

A student kept a notebook during an investigation. Which recorded observation was MOST likely a physical change?

• frying an egg

• toasting bread

• baking a cake

• melting butter

John and Lisa collected a sample of ocean water and placed it in a jar. Within a couple of days, the water had evaporated and salt was visible at the bottom of the jar. This is an example of a

• physical change

• solvent being dissolved

• chemical change

• new substance being formed

Tags

NGSS.MS-PS1-4

A chemist observed bubbling and fizzing after adding an acid solution to a white powdery substance in a beaker. Which of the following can be inferred?

• a physical reaction produced a gas mixture

• the acid and powder formed a new product

• the acid boiled when poured into the beaker

• a reaction occurred that produced heat

Tags

NGSS.MS-PS1-2

Students performed an investigation on how aluminum cans taken to a recycle center were able to be reused. They found out an aluminum can undergoes which type of change?

• a physical change because the can is heated

• a chemical change because an old can is changed into a new can

• a chemical change because new metal is formed

• a physical change because the material remains the same

Tags

NGSS.MS-PS1-2

What is needed to change ice into water?

• air

• stirring

• energy

• chemicals

Tags

NGSS.MS-PS1-4

Which best represents a physical change?

• bubbling

• formation of a precipitate

• condensation

• formation of a new substance

Which best demonstrates a physical change?

• change in temperature

• change in state

• formation of a gas

• unexpected color change

What kind of properties can only be observed when a substance changes into a different substance?

• physical properties

• chemical properties

• liquid properties

• real properties

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5