Unit 3 Review

Scientists

100

Which Scientist thought the Atom was a solid sphere?

John Dalton

200

What Did JJ Thompson Discover and what was his experiment?

Electrons, The Cathode Ray Rxpiriment

300

What was wrong about the Plum Pudding model?

It is missing the nucleus

400

What experiment did rutherford perform?

Gold foil expiriment

500

What did Bohr Discover

That electrons existed in energy shells

Isotopes

100

^A_BX^C  

Which letter represents the Atomic number?

B

200

^A_BX^C   

Whick letter is the mass?

A

300

^A_BX^C

How do you find the number of neutrons?

A-B

400

What element has a mass of 107 and has 60 neutrons?

Ag

500

How many Neutrons does ²⁰⁴₈₁Ti have?

204-81=123

Ions

100

What is the charge of a cation?

pawsitive

200

If an element has a charge of -3 what happened to its electrons?

gained 3

300

if an element has no charge how many electrons does it have?

same number as protons/ =Atomic #

400

How many electrons does Cu⁺¹ have?

28

500

How many electrons does Sn^-4 have?

54

Bohr Model/Lewis dot structure

100

Electrons on the outer layer are called what?

Valence

200

How many electrons can fit on each level?

(Hint) 2 answers

2 on the first level

8 on the rest

300

draw the lewis dot structure for Potassium

one dot

400

draw the lewis dot structure for iodine

7 dots

500

what part of the periodic table tells us how many valence electrons an element has?

group number

Average Atomic Mass

100

What is the formula for average atomic mass?

(mass1)(%1)+(mass2)(%2)=

200

What does the average atomic mass shown on the periodic table represent?

the average of all known isotopes

300

What is the atomic mass if en element is 80% Cr-51, 20% Cr-52

51.2 amu

400

what is the average atomic mass if 30% Re-185, 50% Re-186, 20% Re-187

185.9 amu

500

if the Average atomic mass of Oxygen is 15.99 and has three isotopes

80% Oxygen 16

15% Oxygen 17

5% Oxygen ???what is the missing isotope?

12.8