Understanding chemical reactions

Matter can undergo two types of reactions what are they ?

• chemical and mental

• physical and chemical

• physical and mental

• physical and directional

A physical change does not produce new substances ?

• True

• False

Answer explanation

A physical change does not produce new substances. The substances that exist before and after the change are the same, although they might have different physical properties

The starting substances and the substances produced have the same physical and chemical properties

• True

• False

What is a chemical reaction?

• A chemical reaction is a description of a reaction using element symbols and chemical formulas.

• A chemical reaction is a process in which atoms bond to form a compound.

• A chemical reaction is a process in which atoms of one or more substances rearrange to form one or more new substances.

What are signs of a chemical reaction?

• odor

• state of matter

• color

• all of the above

If substances get warmer or cooler or if they give off light or sound, it is likely that a reaction has occurred.

• true

• false

you can be 100% sure, that a chemical reaction happens if the physical properties have changed

• true

• false

the only way to make sure if the substance had a chemical reaction is by?

• studying the physical properties of the substances before and after the change.

• studying the natural properties of the substances before and after the change.

• studying the elements properties of the substances before and after the change.

• .

  studying the chemical properties of the substances before and after the change.

there are a few types of substances what are they?

• elements

• metals

• mixture

• compound

In a chemical reaction, atoms of elements or compounds rearrange and form different elements or compounds?

• False

• True