Atomic Structure

Question 1

JJ Thomson used a cathode-ray tube to discover that all atoms contained smaller, negatively charged pieces called ______

Answer 1

Electrons, e-

Question 2

Ernest Rutherford’s gold foil experiment showed that the positive charge of an atom was concentrated in a very small ______

Answer 2

Nucleus

Question 3

The ________ ___________ of an element indicates how many protons it has

Answer 3

Atomic number

Question 4

The mass number is the sum of the ______ and ______ in the nucleus

Answer 4

Protons, neutrons

Question 5

Isotopes are atoms of the same element that have different numbers of ______ and therefore have a different _______

Answer 5

Neutrons, mass

Question 6

The ________ _________ mass is a weighted average of all the known isotopes of an element and is recorded on the Periodic table

Answer 6

Average atomic

Question 7

The _______ mass of an element is the mass in grams of one mole of atoms of that element.

Answer 7

Molar

Question 8

Avogadro’s number, _______ is the number of atoms or molecules in one mole.

Answer 8

6.02 • 10^23

Question 9

To convert between grams and moles you use the ____ ______ of the element.

Answer 9

Molar masses

Question 10

A _____ is a positive ion. It is positive because it has _____ electrons

Answer 10

Cation, lost

Question 11

An _____ is a negative ion. It is negative because it has ______ electrons

Answer 11

Anion, gained

Question 12

Dalton’s Atomic Theory described atoms of being small and ______ particles

Answer 12

Unbreakable