Elements, Compounds and Mixtures

What is a compound?

• Two or more different substances that are not chemically bonded

• Two or more atoms of the same element that are chemically bonded

• Two or more atoms from different elements that are chemically bonded

• Two or more different substances that are mixed but not bonded to each othe

Which of the following statements is true (there may be more than one answer)?

• A molecule consists of two or more atoms that are chemically bonded.

• A molecule must be made of only one kind of atom.

• A molecule may consist of the same type of atoms, or atoms from different elements.

• H₂O is a molecule

Tags

NGSS.MS-PS1-1

True or False: all compounds are molecules

• True

• False

Tags

NGSS.MS-PS1-1

This image shows:

• A mixture of elements

• A mixture of compounds

• A mixture of elements and compounds

Tags

NGSS.MS-PS1-1

What is the expression that represents this image?

• CH₄N₂O₂

• C +H₄ + N₂O₂

• H₂O + N₂O + CH₂

• C + H₂ +N₂O

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

Which of the following statements about elements is FALSE?

• Elements cannot be broken down farther and maintain their properties

• Elements are found on the periodic table

• Elements in a molecule can be easily separated by physical means

• Elements bond together to form compounds

Which of the boxes on the left represent a mixture?

• A, B, C

• E, F, H

• B, C, G

• D, G, H

Which of the boxes on the left represents only elements?

• A, D, H

• E, F, H

• C, G, I

• A D, I

True or False: Mixtures can be separated by various techniques such as evaporation, magnetic separation and filtration.

• True

• False

Which of these is NOT a mixture?

• Air

• Trail Mix

• Salt Water

• CO₂