Unit- 2 Atoms And Elements

Question 1

What are the 2 properties to describe matter?

Answer 1

Physical property and chemical property

Question 2

What is physical property?

Answer 2

can be observed without changing
the identity of the substance – examples:
• color
• texture
• density
• Solubility
• malleability

Question 3

What is Chemical property?

Answer 3

describes the ability of a substance to undergo changes in identity

A new substance is produced

examples:
• Reactivity • tarnishing • oxidation

Question 4

What is physical change?

Answer 4

Properties remain the same

changes the form of a substance without changing
its identity

All changes in state! (freeze, melt, condense, evaporate, and sublimate)

Examples:
• Boil, dissolve, break, split, crack, grind, cut, crush, and bend.

Question 5

What is Chemical change?

Answer 5

changes the identity of a substance

a new substance is produced

Examples:
• rust, rot, burn, decompose, corrode, oxidize, ferment,
and explode!

Evidence of a chemical change:
• change in color or odor, formation of a gas, formation of a precipitate (solid), change in light or heat

Question 6

Why do atoms bond together?

Answer 6

It’s all about electrons atoms like to have a full outer shell of electrons ether 2 or 8 depending on the shell

They will ether steal or share electrons to make this happen

Question 7

What charge are protons?

Answer 7

They are positively charged

Question 8

What charge are neutrons?

Answer 8

They have no charge

Question 9

What charge are electrons?

Answer 9

They are negatively charged