Unit 3: atoms and the periodic chart Flashcards Preview

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Flashcards in Unit 3: atoms and the periodic chart Deck (39):
1

proton

a positively charged particle in the nucleus

symbol: p+

2

neutron

a neutral particle (has no charge) in the nucleus

symbol: n0

3

electron

a negatively charged "particle" outside the nucleus

(actually more of a wave than a particle) 

symbol: e-

4

ion

a charged atom or molecule

Examples: Na+, OH-, Al+3

5

cation

a positively charged atom or molecule

Examples: Na+, NH4+

6

anion

a negatively charged atom or molecule

Examples: Cl-, SO4-2

7

isotope

one type (weight) of an element

A difference in the number of neutrons

Examples: carbon-12 and carbon-14

8

atomic mass

a weighted average of the naturally occurring isotopes of an element

the bigger number on the periodic chart, with decimals

# protons + # neutrons = atomic mass

9

How do you find the number of electrons?

find the atomic number and adjust for the charge

 

Example: F-

atomic number 9 + 1 extra electron = 10 e-

10

atomic number

the number of protons

the smaller number on the periodic chart

a whole number

11

How do you find the number of protons?

Look at the element's atomic number.

12

How do you find the number of neutrons?

Subtract the atomic number from the atomic mass.

13

Rutherford's experiment

Shot alpha particles (helium nuclei) at a thin piece of gold foil. Some particles went straight through, others were deflected. Demonstrated that atoms are mostly empty space with a dense core (nucleus). Disproved the plum pudding model.

14

Bohr's experiment

He electrified hydrogen gas until it glowed then separated the light with a prism. Demonstrated that there are particular wavelengths of light being given off, which is characteristic of the element. The atomic spectrum shows how much energy is released by the excited electrons falling back down to the ground state.

15

Which atom has the larger atomic radius, Ca or Ca+2?

Ca

They have the same number of protons. Ca has two more electrons, which makes its electron cloud larger.

16

Which atom has the larger atomic radius, F- or Na+?

F- They have the same number of electrons (10).

F has 9 protons and Na has 11. More protons pull in the electron cloud more, which makes Na+ the smaller atom.

17

alpha decay

A radioactive atom breaks apart into two atoms, a helium nucleus (2 protons and 2 neutrons) and the left overs.

18

beta decay

A radioactive atom breaks apart into an atom and an electron. One of the neutrons splits into a proton and an electron.

19

4 sources of the elements

1-4 Big Bang

5-26 stellar fusion (the star's life)

27-92 super nova (star death)

93+ man made

20

alkali metals

first column

+1 charge

float

react with water

form bases

21

alkali earth metals

second column

+2 charge

not as reactive as alkali metals

22

transition metals

middle of the periodic chart

very stable (gold, silver, copper)

bright colors (sapphire, ruby, emerald, paint, etc)

can be +1, +2, or +3 charges

23

metals

low electronegativity

good conductors of heat and electricity

malleable and ductile

form cations

24

nonmetals

high electronegativity

gasses or brittle solids

poor conductors

form anions

25

hallogens

7th column

-1 charge

very reactive

tend to form acids

diatomic (F2, Cl2, Br2, I2)

26

Noble gases

8th column

no charge

completely stable; don't react with anything

full s and p orbitals

27

energy level

the row number

28

valence electrons

the electrons in the outer energy level

same number as the column number

shown as dots around the symbol in a Lewis Dot Diagram

29

electron configuration

A list of where the electrons reside in the electron cloud. Can be abbreviated using the nearest noble gas.

30

quantum numbers

the 4 variables which define an orbital: n, l, ml, ms

The numbers are inserted into equations and graphed.  The 3D graph shows the space where the electron is most likely to be found (the orbital).

31

orbital

the region of space where an electron is likely to be found

Each orbital can hold two electrons (of opposite spin)

32

s orbital

spherical

there is a single s orbital at every energy level

 

33

p orbital

dumbell shaped

there are 3 p orbitals at every energy level except the first level

34

d orbital

various shapes, including clover leaf

there are 5 d orbitals in the 3rd energy level and at all the higher energy levels

35

f orbital

various shapes

4th energy level and above

there are 7 different f orbitals

36

s block elements

Alkali metals and Alkali Earth metals

37

p block elements

columns 3-8

includes all the nonmetals

38

d block elements

the transition metals

because of the d orbitals, these elements have more than one stable charge

Ex: Fe+2 and Fe+3 

39

f block elements

lanthanides and actinides (bottom two rows of periodic chart)