unit 2 chem test

Question 1

matter

Answer 1

anything with mass that takes up space

Question 2

atomic mass unit

Answer 2

u or amu

Question 3

atomic mass

Answer 3

weighted average of the masses of the isotopes that make up elements

Question 4

how to calc atomic mass

Answer 4

multiple percent by the mass of the dif isotopes separately and add up the result.

Question 5

molecular mass

Answer 5

the sum of masses of the atoms in a molecule

Question 6

ex of molecular mass: N2O3

Answer 6

2N = 2 x mass of one =
3O= 3 x mass of one =

Question 7

water electrolysis

Answer 7

breaking water into hydrogen and oxygen

Question 8

green hydrogen

Answer 8

producing hydrogen with renewable energy

Question 9

fuel cells

Answer 9

convert hydrogen and oxygen back into water

Question 10

hydrogen gas

Answer 10

produced through natural gas by SMR (steam methane reforming)

Question 11

hydrogen > energy

Answer 11

hydrogen is high density energy and has an ease of storage and transport

Question 12

hydrogen > battery

Answer 12

hydrogen has long-duration energy storage and high-density energy

Question 13

textbook chemistry

Answer 13

study of the world around us and the change in matter

Question 14

solid - gas

Answer 14

sublimation

Question 15

solid to liquid

Answer 15

melting

Question 16

liquid to gas

Answer 16

evaporation

Question 17

gas to solid

Answer 17

deposition

Question 18

liquid to solid

Answer 18

boiling

Question 19

gas to liquid

Answer 19

condensation

Question 20

pure substance matter

Answer 20

when particles are identical

Question 21

atoms

Answer 21

the smallest unit of matter

Question 22

mixture matter

Answer 22

when particles are different

Question 23

elements

Answer 23

pure substances made of only one atom

Question 24

molecule

Answer 24

2+ atoms chemically bonded

Question 25

compound

Answer 25

pure substance made of 2+ atoms or elements

Question 26

difference between molecules and compunds

Answer 26

A molecule is the smallest unit of a substance that retains its chemical properties. Molecules can be independent and not necessarily part of compounds. A compound is a specific type of molecule made up of different elements, it is a subset of molecules. molecules dont need to be pure subs while compunds are

Question 27

chemical bond

Answer 27

when atoms are touching

Question 28

subscripts

Answer 28

how many atoms are present

Question 29

pure substance

Answer 29

when particles are identical

Question 30

mixture

Answer 30

dif types of particles

Question 31

isotope notation

Answer 31

low = atomic number, top = mass number, big = element letter(s)

Question 32

atomic number

Answer 32

protons in nucleus

Question 33

mass number

Answer 33

Protons + nuetrons in element

Question 34

what subatomic particle differs between isotopes

Answer 34

nuetrons

Question 35

what subatomic particle determines element

Answer 35

protons

Question 36

neutral atoms

Answer 36

no charge, same number of protons and electrons

Question 37

positive ions

Answer 37

less electrons than protons, cations

Question 38

negative ions

Answer 38

less protons than electrons, anions

Question 39

net charge

Answer 39

charge of protons + charge of electrons. ex: C has 6 p and 5n, the charge would be +1 and a positive ion or cation

Question 40

why don't protons change in isotopes

Answer 40

because then the element would change

Question 41

isotopes

Answer 41

form of a given element where the # of n varies (therefore so does mass # and atomic #)