Chemistry Review

An element is...

• a group of atoms bonded together in a set ratio

• a substance made of one type of atom

• a substance made up of 2 atoms

• a group of atoms bonded together

Which of the following is a heterogeneous mixture?

• Soda

• Coffee

• milk

• spaghetti

According to the Law of Conservation of mass the mass of the _________ must equal the mass of the _________.

• compounds, mixtures

• reactants, products

• elements, chemicals

• substances, destroyed

Tags

NGSS.MS-PS1-5

Which is evidence of a chemical reaction?

• the appearance of rust on a pail after rainfall

• the appearance of water droplets on the outside of a cup of cold water

• the disappearance of a solid when it dissolves in water

• the appearance of frost on a carton of ice cream

Tags

NGSS.MS-PS1-2

What are electrons on the outer shell of an atom called?

• 2-8-8 rule

• happy electrons

• valence electrons

• outer electrons

If an atom is missing 2 electrons in its valence shell it will _______ electrons.

• take

• give

If an atom has 5 valence electrons it will __________ electrons.

• give

• take

Atoms want to bond together because:

• they are happy

• they like being with friends

• they have 8 electrons

• they want a full valence shell

Things float in water because:

• they are more dense than water

• they are less dense than water

• they are more acidic than water

• they are more basic than water

Which element is in group 4 of the periodic table?

• Titanium (Ti)

• Berylium (Be)

• Potassium (K)

• Lithium (Li)