Chemistry Unit Review 1

Which of the following substances are elements?

• water

• salt

• carbon dioxide

• hydrogen

How many elements are in this Carbon dioxide molecule?

• 3

• 2

• 1

• 0

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NGSS.MS-PS1-1

Which of the following is an element?

• A

• B

Whys is B considered to be a compound?

• It is made of more than one element.

• It can be broken down into the elements that comprise it.

• It's a pure substance composed of 2 kinds of atoms.

• All are true

How many elements are in this potassium chloride (KClO₃) molecule?

• 3

• 4

• 5

• 6

What is true of both elements and compounds?

• They are always made of more than one element.

• They are large.

• They don't last long.

• They are considered to be pure substances.This is a correct answer

Evaporating, dissolving, & melting are all examples of

• elements

• compounds

• physical changes

• chemical reactions

Which of the following is not evidence of chemical change?

• gas production

• temperature change

• dissolving

• color change

Tags

NGSS.MS-PS1-2

This symbol indicates a _______.

• neutron

• proton

• electron

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NGSS.MS-PS1-1

What 2 elements make up water?

• Hydrogen and Carbon

• Carbon and Oxygen

• Hydrogen and Oxygen

• Oxygen and Helium

Tags

NGSS.MS-PS1-1