1.1 - Intro to the particle nature of matter and chemical change

Question 1

absolute zero

Answer 1

0 Kelvin and -273 Celsius

Question 2

Describe what happens when ice is heated in 4 steps

Answer 2

1) the particles vibrate more until it reaches melting point (absolute zero)
2) then the ice melts but temp stays the same because the energy is used to break the attractive forces which will allow the molecules to move more freely
3) once melted the heat makes the water molecules vibrate more until it boils (100 C, or 373 K)
4) once water boils the temp won’t change again b/c energy is being used to overcome attractive forces

Question 3

endothermic process

Answer 3

when the system absorbs heat (ex, melting and boiling)

Question 4

exothermic process

Answer 4

when the system releases heat (ex, freezing)

Question 5

condensation

Answer 5

gas to liquid

Question 6

vaporisation/evaporation

Answer 6

liquid to gas

Question 7

sublimation

Answer 7

solid to gas

Question 8

deposition

Answer 8

gas to solid

Question 9

melting

Answer 9

solid to liquid

Question 10

freezing

Answer 10

liquid to solid

Question 11

element

Answer 11

contains only one type of atom

Question 12

compounds

Answer 12

a combination of atoms

Question 13

pure substance

Answer 13

matter that has a constant composition (ex. elements and compounds)

Question 14

mixture

Answer 14

when pure substances combine

Question 15

homogenous mixture

Answer 15

has uniform composition, the various substance mix and blend together

Question 16

heterogeneous mixture

Answer 16

has non-uniform composition, the alike substances stick together and don’t blend as one

Question 17

ion

Answer 17

an atom or group of atoms

Question 18

anion

Answer 18

a positively charged ion

Question 19

cation

Answer 19

a negatively charged ion

Question 20

combination/synthesis reaction

Answer 20

two or more substances combine to make a single product

Question 21

decomposition reaction

Answer 21

a single reactant being broken down into two or more products

Question 22

single replacement reactions

Answer 22

one element replaces another in a compound

Question 23

atom economy

Answer 23

assesses efficiency of chemical reactions (calculated by: molecular mass of atoms of useful producs/ molecular mass of atoms in reactants -> times 100%)

Question 24

double replacement reaction

Answer 24

occurs between ions in solutions to form insoluble substances(won’t dissolve) and metathesis reactions