Unit 2 Test

Question 1

what are 3 subatomic particles and what does each one do

Answer 1

protons: determine identity of an element
neutrons: hold nucleus together and influence mass
electrons: determine the chemical properties of an element

Question 2

how do their masses compare (according to 1)

Answer 2

protons/neutrons= same mass (1.67 x 10^-24)
electrons= (9.11 x 10^-28)

Question 3

how do electrons emit light?

Answer 3

when an electron moves from a high to a low energy level it results in a burst of light

Question 4

how many electrons can be held in the third principal energy level

Answer 4

18

Question 5

how many sublevels are in the 2nd principal level

Answer 5

2

Question 6

how are the elements arranged on the modern periodic table

Answer 6

increasing atomic number

Question 7

how many neutrons doe Rn-226 have?

Answer 7

140

Question 8

How does an isotope differentiate from a neutral atom?

Answer 8

Isotopes have the same # of protons but a different # of neutrons.
(also all have different mass numbers)

Question 9

Where are neutral atoms found?

Answer 9

periodic table

Question 10

Difference between atomic mass and mass number? what do each represent?

Answer 10

atomic mass: weighted average mass of atoms in a naturally occurring sample of the element, reflects both the mass and relative abundance.
mass number: # of protons + neutrons

Question 11

what is the stability of an isotope based on?

Answer 11

ratio of neutrons to protons

Question 12

which type of nuclear emission is the most similar to high x-rays?

Answer 12

gamma

Question 13

how does the atomic emission spectrum compare to the visible spectrum

Answer 13

visible spectrum: only small chunk (rainbow colors)

atomic emission: everything

Question 14

what determines a element’s chemical properties?

Answer 14

electrons

Question 15

how do elements configuration relate to their position on the periodic table

Answer 15

they show the amount of electrons (atomic number) and where they are located

Question 16

whats the difference between an ion and a neutral atom

Answer 16

Ion has a different number of protons/electrons

Question 17

describe modern atomic theory

Answer 17

electrons exist in a cloud

Question 18

difference between physical and chemical change

Answer 18

chemical: change that produces matter with a different composition than the original matter
physical: some properties of a material change but the composition of the material does not change

Question 19

signs of a chemical change

Answer 19

• forms a precipitate
• release of energy
• bubbles
• change of color

Question 20

what types of substances cant be broken down by chemical processes

Answer 20

elements

Question 21

differences and definitions of the different types of decay

Answer 21

alpha:
-nucleus ejects 2 protons and neutrons simultaneously
-atomic # down 2
-atomic weight down 4
beta:
-neutron splits into proton and electron
-atomic # up 1
-atomic weight = no change
gamma:
-no change, just emits radiation (deadly)

Question 22

what is a half-life?

Answer 22

the time required for one-half of the nuclei of a radioisotope sample to decay to products

Question 23

how much of a 1000g sample would be left after 4 half-lives?

Answer 23

500>250>125>(62.5)

Question 24

what do the symbols represent in the equation:

c=(upside down)Yv

Answer 24

C= speed of light (m/s)
(upside down) Y= wavelength (m/s)
v= frequency (sec^-1)

Question 25

what do the symbols represent in the equation: | E=hv

Answer 25

``` E= energy (joules) h= Planck's Constant (J*sec) v= frequency (hertz or sec^-1) ```

Question 26

what is atomic number

Answer 26

of electrons/protons

Question 27

what do the symbols represent in the equation: | a/zC

Answer 27

``` a= protons + neutrons (mass number) z= protons c= element name ```

Question 28

what are two ways to write isotopes?

Answer 28

element name- mass number | mass #/protons x element name

Question 29

what are the two types of isotopes

Answer 29

stable: nucleus stays intact unstable: nucleus decays and emits radiation

Question 30

define fission and fusion

Answer 30

fission: when atom divides into smaller parts (EX: nuclear energy, bomb) fusion: when 2+ atoms fuse together to become one (EX: stars, new elements)

Question 31

strengths of the 3 types of decay?

Answer 31

alpha: encounter everyday beta: skin protects us from it gamma: goes through everything

Question 32

define atomic orbitals

Answer 32

space around the nucleus where the electrons exists

Question 33

each principal energy level surround the nucleus has a _________

Answer 33

specific # of sublvls within it

Question 34

each sublvl has a specific _______

Answer 34

shape & is designated by a letter

Question 35

each sublvl can only hold a certain ________

Answer 35

of electrons

Question 36

define aufbau principle

Answer 36

electrons fill the lowest energy lvls first

Question 37

define pauli explusion principle

Answer 37

only 2 electrons can share an orbital and they have opposite spin

Question 38

define hunds rule

Answer 38

electrons spread out of their last orbital

Question 39

define light

Answer 39

a stream of photons (packets of energy)

Question 40

what do different colors indicate

Answer 40

different wavelengths

Question 41

what is white a combination of

Answer 41

all the colors (light reflects color)

Question 42

different wave lengths carry different ________

Answer 42

amounts of energy

Question 43

first step:

Answer 43

receive energy and become excited

Question 44

when electrons get excited:

Answer 44

they absorb energy and move up an orbital from their ground state

Question 45

when they return to their ground state:

Answer 45

the energy is released in the forms of light. The color of the light depends on how much color it has

Question 46

define amplitude, wavelength and frequency

Answer 46

amplitude: waves height from bottom to top wavelength: distance between crests (tops) of wave frequency: # of wave cycles to pass a given point

Question 47

define quantum

Answer 47

amount of energy to move lvls

Question 48

define electron configurations

Answer 48

way electrons are arranged in various orbitals around nuclei

Question 49

wavelength and frequency are:

Answer 49

inversely proportional

Question 50

what is red on the visible spectrum

Answer 50

longest wavelength, lowest frequency