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Flashcards in Unit 2 Test Deck (50):
1

what are 3 subatomic particles and what does each one do

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

2

how do their masses compare (according to 1)

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

3

how do electrons emit light?

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

4

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

18

5

how many sublevels are in the 2nd principal level

2

6

how are the elements arranged on the modern periodic table

increasing atomic number

7

how many neutrons doe Rn-226 have?

140

8

How does an isotope differentiate from a neutral atom?

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

9

Where are neutral atoms found?

periodic table

10

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

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

11

what is the stability of an isotope based on?

ratio of neutrons to protons

12

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

gamma

13

how does the atomic emission spectrum compare to the visible spectrum

visible spectrum: only small chunk (rainbow colors)
atomic emission: everything

14

what determines a element's chemical properties?

electrons

15

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

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

16

whats the difference between an ion and a neutral atom

Ion has a different number of protons/electrons

17

describe modern atomic theory

electrons exist in a cloud

18

difference between physical and chemical change

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

19

signs of a chemical change

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

20

what types of substances cant be broken down by chemical processes

elements

21

differences and definitions of the different types of decay

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)

22

what is a half-life?

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

23

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

500>250>125>(62.5)

24

what do the symbols represent in the equation:
c=(upside down)Yv

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

25

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

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

26

what is atomic number

# of electrons/protons

27

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

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

28

what are two ways to write isotopes?

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

29

what are the two types of isotopes

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

30

define fission and fusion

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

31

strengths of the 3 types of decay?

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

32

define atomic orbitals

space around the nucleus where the electrons exists

33

each principal energy level surround the nucleus has a _________

specific # of sublvls within it

34

each sublvl has a specific _______

shape & is designated by a letter

35

each sublvl can only hold a certain ________

# of electrons

36

define aufbau principle

electrons fill the lowest energy lvls first

37

define pauli explusion principle

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

38

define hunds rule

electrons spread out of their last orbital

39

define light

a stream of photons (packets of energy)

40

what do different colors indicate

different wavelengths

41

what is white a combination of

all the colors (light reflects color)

42

different wave lengths carry different ________

amounts of energy

43

first step:

receive energy and become excited

44

when electrons get excited:

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

45

when they return to their ground state:

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

46

define amplitude, wavelength and frequency

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

47

define quantum

amount of energy to move lvls

48

define electron configurations

way electrons are arranged in various orbitals around nuclei

49

wavelength and frequency are:

inversely proportional

50

what is red on the visible spectrum

longest wavelength, lowest frequency