quiz 3

Question 1

q=MC∆T

Answer 1

q= energy IN JOULES
M= mass IN GRAMS
C= heat capacity in j/gc
∆T= temp change IN CELSIUS

Question 2

thermal equilibrium

Answer 2

in the process of heat transferring from one substance to another, if given enough time, the end result will always be that they are the same temperature
(no conservation of temp bc temp is not energy)

Question 3

in the example of the water and the lead block, their relationship can be summarized by

Answer 3

q water= -q lead block

as the ∆T for the water is positive while it is neg for the lead block

Question 4

atomic theory

Answer 4

all matter is composed of atoms

Question 5

elements are composed of one type of

Answer 5

atom

Question 6

john daltons atomic theory

Answer 6

1. each element is composed of tiny indestructible particles called atoms, which are all conserved (neither created nor destroyed) during a chemical change, just rearranged into different combinations
2. if two atoms are of the same element, they will be completely identical. if its 2 of different elements, they’ll be different
3. atoms combine in simple, whole-number ratios to form compounds. no element is found as a fraction of an atom

Question 7

plum pudding model

Answer 7

1. atom’s mass is spread throughout the atom
2. positive charges are spread throughout the atom
3. neg charges are balanced out by positive charges

proposed by thompson, disproven by his protege rutherford

Question 8

Nuclear Model

Answer 8

1. atom’s mass is concentrated at the nucleus
2. positive charge is concentrated at the nucleus
3. neg charges balanced out by pos charges (that didnt change from plum pudding model)

proposed by rutherford to correct his mentor thompson’s plum pudding model

Question 9

subatomic particles

Answer 9

compose atoms

1. protons with +1 charge
2. neutrons with no charge
3. electrons with -1 charge

Question 10

mass of a neutron vs proton

Answer 10

almost exactly the same (around 1 amu, or 1.67*10^-27 kg)

Question 11

the atomic number of an element

Answer 11

• the top number on an entry in the periodic table
• indicates the # of protons that element will always have (thats what makes it that element)
• also known as Z

Question 12

the atomic mass

Answer 12

• the bottom number on an entry in the periodic table
• indicates the mass in amu of one atom of that element
• is a WEIGHTED average that takes the natural abundance of each isotope into account

Question 13

rows in the periodic table are referred to as

Answer 13

periods (7 of them)

Question 14

columns in the periodic table are referred to as

Answer 14

groups (18 of them)

Question 15

4 types of compounds

Answer 15

1. ionic
2. metallic
3. covalent
4. acid

Question 16

metals

Answer 16

can be found
to the left and under the "stairs" (the staircase which "potter" (Po) lives under)
and are
1. ductile (can be drawn into wires)
2. malleable
3. luster (shiny)
4. good conductor of heat
5. good conductor of electricity

Question 17

ions

Answer 17

atoms that lose or gain electrons to form charged particles

Question 18

groups w predictable charges as ions

Answer 18

1. alkali metals: +1
2. alkaline earth metals: +2
3. halogens: -1

Question 19

mass number

Answer 19

• given by variable “A”
• sometimes given as a superscript to the left of the element symbol
• indicates the number of protons + neutrons

Question 20

isotopes

Answer 20

• atoms that have same # of protons, but different # of neutrons.
• same atomic number, different mass number

Question 21

to find weighted average

Answer 21

multiple each mass by its respective abundance (as a decimal, not %) and then add those products

Question 22

to find mass of a compound

Answer 22

determine the amount of each atom present, that multiple each atom’s atomic mass by the amount of atoms present, then add the products

Question 23

ionic compounds

Answer 23

• composed of ions with pos or neg charges, always have a net charge of 0 (neutral)
• start with a metal and end w a nonmetal

Question 24

metallic compounds

Answer 24

are made entirely of metal

Question 25

covalent compounds

Answer 25

are not split into charges, so not split into metal (cation) and nonmetal (anion)

Question 26

acids

Answer 26

always start with “H”

Question 27

alkali metal family

Answer 27

farthest left group

Question 28

alkaline earth metal family

Answer 28

group to the right of the alkali metal group

Question 29

halogen family

Answer 29

group to the left of the noble gases

Question 30

noble gas family

Answer 30

farthest right group, non-reactive

Question 31

mass of an electron

Answer 31

.00055 amu, or .00091*10^-27 kg. it’s 1/2000 of a proton or neutron

Question 32

crystalline

Answer 32

a solid form of matter which has a long range repeating order

Question 33

an x-to-y ratio

Answer 33

is calculated as x/y, and expressed as a whole number.

ex: x=12, y=3, their ratio is 4.

Question 34

melting point

Answer 34

the temp at which a solid becomes a liquid.

below the temp it is a solid, and above, it is a liquid.

Question 35

law of constant composition

Answer 35

all samples of a given compound have the same proportions of their constituent elements