CHEMISTRY: ELEMENTS, COMPOUNDS, AND STATES OF MANNER

Question 1

Element

Answer 1

-simple substance made up of one type of atom
-cannot be broken down to anything simpler
-is a substance because its composition and properties do not vary

Question 2

Compound

Answer 2

-substance made up of two or more different atoms bonded together
-can be broken down into elements
-is a substance because its composition and properties do not vary

Question 3

Matter [solid, liquid, gas]
Gas

Answer 3

-the attractions between the atoms or molecules are weak, and the particles move around in a random and erratic manner
-if placed in a container, gas takes the shape of its container and spreads to fill its volume

Question 4

Matter [solid, liquid, gas]
Liquid

Answer 4

-has more attraction between its particles
-takes the shape of the container it is in, but does not vary in volume

Question 5

Matter [solid, liquid, gas]
Solid

Answer 5

-does not take the shape of its container
-does not flow, and its particles have very little movement

Question 6

Melting

Answer 6

Process that takes a solid to a liquid

Question 7

Evaporation

Answer 7

Process that turns liquid to a gas

Question 8

Condensation

Answer 8

Gas to liquid conversion

Question 9

Freezing

Answer 9

Liquid turns into a solid

Question 10

Sublimation

Answer 10

-the direct change between the solid phase and the gaseous phase without an apparent liquid phase
-ex. iodine undergoes sublimation when heated, and dry ice does the same when exposed to room temperature

Question 11

Phase change

Answer 11

-during a phase change, the amount of heat that is input or extracted from the substance changes, but the temperature remains the same
-this is because all of the heat is being used to change the phase of the substance, not the temperature
-thus, the evaporating and condensing points of water are both 100°C
-all liquids tend to evaporate and all gases tend to condense, eventually reaching equilibrium
-in a closed system, the evaporated gas above a liquid exerts a pressure called vapor pressure, which is specific for each liquid and at each temperature
-for a liquid to boil, its vapor pressure must be equal to the pressure on it
-at high altitudes where the barometric pressure is lower, liquids boil at lower temperatures