Atomic Theory/Structure Review

Question 1

A proton is about the same mass of which other subatomic particle?

Accepted Answer

neutron

Question 2

Atoms of the same element that contain different numbers of NEUTRONS are known as ________

Accepted Answer

ISOTOPES!

Question 3

Based on the average atomic mass of potassium, we can conclude that:

Accepted Answer

the isotope potassium-39 occurs most often in nature

Question 4

What is the relative mass of an electron (compared to protons and neutrons)?

Accepted Answer

about 2000x less massive (1/1836)

Question 5

If an atom LOSES 1 electron, what would its charge be?

Accepted Answer

1+

Question 6

Law of definite proportions: if we have two samples of pure H2O, what would be true about them?

Accepted Answer

Both samples would have exactly the SAME RATIO of ELEMENTS

Question 7

How does the QM model differ from the Bohr model?

Accepted Answer

It doesn't restrict electrons to specific paths

Question 8

Most of the VOLUME of an atom is occupied by ____________

Accepted Answer

the electron cloud

Question 9

How many NEUTRONS are in iron-56? (Symbol: Fe) Use the image below to help.

Accepted Answer

30

Question 10

Why is an atom electrically neutral? Because...

Accepted Answer

the number of protons is equal to the number of electrons

Question 11

All atoms of the same element have the same

Accepted Answer

atomic number

Question 12

In Dalton's Atomic Theory, he claims that:

Accepted Answer

Atoms are indivisible and indestructible

Question 13

Which scientist discovered electrons by performing experiments with cathode rays?

Accepted Answer

J.J. Thomson

Question 14

How many ELECTRONS are in an atom of titanium. Use the shorthand notation below to help.

Accepted Answer

22

Question 15

Rutherford (and his team) discovered that all atoms have what?

Accepted Answer

a small, positively charged nucleus

Question 16

According to the Bohr model of an atom, where can an electron NOT exist? In the nucleus or....

Accepted Answer

in between energy levels

Question 17

How many protons does every isotope of chlorine (Cl) have?

Accepted Answer

17

Question 18

The particles that make up cathode rays are ___________ charged.

Accepted Answer

Negatively

Question 19

The mass number of an atom is defined as:

Accepted Answer

its number of protons and neutrons combined

Question 20

Below are parts of Dalton's Theory. Which part has been UPDATED due to later discoveries?

Accepted Answer

Atoms of the same element are identical in size and mass

Question 21

Which pair of compounds below demonstrates the Law of Multiple Proportions?

Accepted Answer

H2O and H2O2

Questions 21