Chemistry part one

Question 1

What does WHMIS mean?

Answer 1

Workplace Hazardous Materials Information System.

Question 2

What are the three states of matter?

Answer 2

Solid
Liquid
Gas

Question 3

What are properties?

Answer 3

Characteristics used to describe a substance.

Question 4

What are physical properties?

Answer 4

Properties that explain the appearance and composition of a substance.
Ex: Texture, colour, density, melting point

Question 5

What is physical change?

Answer 5

Any change not involving a change in the substance’s chemical identity. Changes only in physical properties.
Ex: Change of state (melting, freezing, evaporating)

Question 6

What are chemical properties?

Answer 6

They explain how a substance reacts with another substance.
Ex: Ph, Reactivity, Toxicity

Question 7

What is chemical change?

Answer 7

Two or more substances that react and one or more new substance(s) are formed having different properties.
Ex: Combustion, Burning

Question 8

What is a pure substance?

Answer 8

Consists of only one kind of matter and has its own unique set of properties. Elements and compounds are pure substances. Ex: water, gold

Question 9

What is an element?

Answer 9

A material that cannot be further broken down. Building blocks for compounds.

Question 10

What are Compounds?

Answer 10

Two or more elements chemically combined in a specific arrangement and proportion.

Question 11

What is a mixture?

Answer 11

A physical combination of pure substances. Each substance retains its properties since there is no chemical reaction that takes place. Ex: Kool Aid, Butter and flour

Question 12

What are the four types of mixtures?

Answer 12

1) Mechanical mixture- each substance that makes up the mixture is distinct or visible.
2) Solution- the substances are not visible or distinct
3) Suspension- tiny particles of one substance is held within another cloudy mixture. The particles can be filtered out.
4) Colloid- Another cloudy suspension but the particles cannot be filtered out.

Question 13

What is solute and solvent?

Answer 13

Solute- the thing being dissolved
Solvent- the thing the solute is being dissolved in

Question 14

What is the Tyndall affect?

Answer 14

Light is scattered when put through the substance due to the particles.

Question 15

What is evidence of chemical change?

Answer 15

1) Change in colour
2) Change in Odour
3) Formation of solid or gas (precipitation)
4) Release or absorbtion of heat (exo or endothermic)

Question 16

What did John Dalton do?

Answer 16

He suggested that matter is made up of solid spheres called atoms.

Question 17

What did J.J.Thomson do?

Answer 17

He suggested that electrons are embedded in the atom.

Question 18

What did Hantaro Nagoka do?

Answer 18

He refined the idea saying electrons orbit the central positive mass.

Question 19

What did Ernest Rutherford do?

Answer 19

He suggested that the nucleus is made up of protons.

Question 20

What did Bohr do?

Answer 20

He suggested that electrons exist in specific motions.

Question 21

What did James Chadwick do?

Answer 21

He refined the idea suggesting the nucleus is made up of positive charged protons and neutral neutrons.

Question 22

What did Quantum Mechanics do?

Answer 22

They found that electrons exist in a charged cloud around the nucleus.

Question 23

Who organized the Periodic table of elements? How did he do it?

Answer 23

Dimitri Mendeleev.
He wrote them on cards and arranged them until he found a pattern. This layout followed increasing atomic mass and grouped elements with similar properties.

Question 24

What are periods?

Answer 24

Horizontal rows, numbered 1-7.

Question 25

What are groups/families?

Answer 25

Vertical rows, numbered 1-18. Elements in the same group have similar properties.

Question 26

What is Group One?

Answer 26

Hydrogen and Alkali Metals. Most reactive metals, react with water and air, reactivity increases as you move down the group.

Question 27

What is Group Two?

Answer 27

Alkaline-Earth Metals. They react with air and water but are less reactive than alkali metals.

Question 28

What is Group seventeen?

Answer 28

Halogens. They are the most reactive non-metals and tend to combine with other elements to make compounds.

Question 29

What is Group Eighteen?

Answer 29

Noble gases. The most stable and unreactive elements.

Question 30

What is Atomic number?

Answer 30

How many protons are in the nucleus of an atom of an element, same as the number of electrons.

Question 31

What is Mass Number?

Answer 31

The total mass of all protons and neutrons in an atom.

Question 32

How do you calculate the number of neutrons?

Answer 32

Subtract the Atomic number from the atomic mass.

Question 33

What are the properties of a metal?

Answer 33

• shiny
• malleable
• ductile
• conducts electricity

Question 34

What are the properties of a non-metal?

Answer 34

• can be a solid or a gas
• dull and/or brittle (only for solids)
• does not conduct electricity

Question 35

What is Atomic mass?

Answer 35

Quantity of matter in an atom.