Chem

Question 1

What Does “WHMIS” stand for?

Answer 1

Workplace Hazardous Materials Information System

Question 2

What is the purpose of WHMIS?

Answer 2

WHMIS is designed to ensure that people working with
chemicals know how to:
-handle chemicals safely
-dispose of them safely

Question 3

What does “MSDS” stand for?

Answer 3

Material Safety Data Sheet

Question 4

All chemicals are shipped with a “MSDS”, what do these sheets include?

Answer 4

-Scientific Names and other common Names
-Physical Properties
-Chemical Hazards
-How to Handle, Store, and Dispose of them Properly
-The procedure to follow in case of an incident

Question 5

What 2 types of change can a substance go through?

Answer 5

Chemical and Physical

Question 6

What is Chemical Change?

Answer 6

-When substances react with each other, their atomic/molecular structure changes
-Bonds are broken and reformed to form new substances
-Chemical changes are difficult, if not impossible, to reverse

Question 7

What is Physical Change?

Answer 7

-A substance changes in form but not in chemical composition
-No new substances are formed

Question 8

Who are the 4 old dudes?

Answer 8

John Dalton, JJ Thomson, Ernest Rutherford, and Niels Bohr

Question 9

What is Dalton’s Atomic Theory?

Answer 9

-All matter is made up of small particles called atoms
-Atoms cannot be created, destroyed, or divided into smaller particles.
-Compounds are formed when atoms of different elements combine in fixed, or definite, proportions.
-Chemical reactions change the way atoms are grouped, but the atoms themselves are not changed in reactions.
-All atoms of the same element are identical in mass and size, but they are different in mass and size from the
atoms of other elements.

Question 10

What is Dalton’s Theory referred to as?

Answer 10

The Billiard Ball Theory

Question 11

What is the JJ Thomson Atomic Theory? And what did he use the determine this?

Answer 11

JJ Thomson used the Cathode ray to determine that the “ray” was actually a stream of negatively charged objects.

He proposed that atoms were a sphere of positive charge in which negative particles were embedded

Question 12

What was JJ Thomson Theory called?

Answer 12

It is commonly referred to as either the “Raisin Bun Theory” or the ““Plum Pudding Model”

Question 13

What was JJ Thomson able to determine with his experiment?

Answer 13

He was able to determine the charge & mass of the electron

Question 14

What was Ernest Rutherford’s Theory? And what was his experiment?

Answer 14

He directed a stream of alpha paritcles (+ charge) toward thin gold foil.
-he predicted that the particles would collide with the gold atoms and change directions slightly

Question 15

Was Rutherford’s prediction wrong? If so why?

Answer 15

It was correct, but there was something unexpected. Some of the particles bounced back from the foil.

Question 16

What did Rutherford conclude from his experiment?

Answer 16

-because most of the particles did bounce on anything he concluded most of the atom was empty space
-whatever the particles bounced back on had to be very small and very positive

Question 17

What did Rutherford propose for the Atom?

Answer 17

Nucleus
-extremely small, contains nearly all the mass of
the atom.
-contains protons (+ charge), and neutrons
(neutral charge).

Electrons (- charge)
-very little mass, move around the nucleus like
planets orbiting the sun.

Question 18

What was Rutherford’s Theory called?

Answer 18

Solar-System Model

Question 19

What did Niels Bohr propose for his theory?

Answer 19

That electrons are found in energy levels,
and cannot be found in between these energy levels.

Question 20

What is the “Bohr Model”?

Answer 20

Electrons orbit the nucleus of an atom in set energy levels.

Question 21

What was the Bohr Model called?

Answer 21

Planetary Model

Question 22

What did James Chadwick discover and conclude?

Answer 22

-After bombarding beryllium atoms with alpha particles, Chadwick discovered
an unknown form of radiation

-He concluded that the presences of another subatomic particle that was
neutral and similar in mass to that of the positive charge in the nucleus

Question 23

What are the respective charges of the Proton, Neutron, and the Electron?

Answer 23

Proton = 1+
Neutron = 0
Electron = 1-

Question 24

In an element how do you determine the number of protons? Number of electrons? And the number of Neutrons?

Answer 24

protons = atomic #
electrons = atomic #
neutrons = mass - atomic #

Question 25

What are Isotopes?

Answer 25

Atoms of the same element that differ in mass but are chemically alike (Twins).

Question 26

3 facts about Isotopes

Answer 26

isotopes of the same atom have the same # of protons, but different # of neutrons

isotopes are named by: name of element - mass # ex. carbon - 14 (has 6 protons, 8 neutrons)

** The # of protons in an atom of any element never
changes.