U.1 Chem

Question 1

Q: What is chemistry the study of?

Answer 1

A: The study of matter (everything except energy).

Question 2

Q: Why is safety important when working with chemicals?

Answer 2

A: Some chemicals can burn your skin or eyes, and most are poisonous.

Question 3

Q: What does WHMIS stand for?

Answer 3

A: Workplace Hazardous Materials Information System.

Question 4

Q: What is the purpose of WHMIS?

Answer 4

A: To provide information symbols for hazardous materials in the workplace.

Question 5

Q: How is WHMIS different from HHPS?

Answer 5

A: WHMIS uses symbols similar to HHPS but includes extra symbols (e.g., for infections) and typically uses only one shape (a circle).

Question 6

Q: What does HHPS stand for?

Answer 6

A: Hazardous Household Products Symbols.

Question 7

Q: Why are symbols used on chemical containers?

Answer 7

A: They are easier to understand than words, especially for those who cannot read or speak the language.

Question 8

Q: What are the four HHPS symbols?

Answer 8

A: Explosive, Corrosive, Poisonous, and Flammable.

Question 9

Q: What do the two HHPS symbol shapes represent?

Answer 9

A:
• Triangle: Less dangerous.
• Octagon: More dangerous (stronger warning).

Question 10

4 rules of P.T

Answer 10

1. All matter is made up of particles.
2. Particles are always moving.
3. When heated the particles move more
4. The particles are held together by bonds

Question 11

List the 3 bonds

Answer 11

1. Solids
2. Liquids
3. Gases

Question 12

Q: Describe the particles in a solid, liquid, & gas

Answer 12

A:
1. Strong bonds, close together, vibrate in place.
2. spaces between them
3. Weak, far apart and move all over.

Question 13

Q: What are the two main categories of matter?

Answer 13

A: Mixtures and Pure Substances.

Question 14

Q: What are the two types of pure substances?

Answer 14

A:
1. Elements (e.g., hydrogen, oxygen)
2. Compounds (e.g., water).

Question 15

Q: What are the 4 types of mixtures?

Answer 15

A:
1. Solution: e.g. sugar in water
2. Suspension: e.g. oil and vinegar
3. Mechanical Mixture: e.g. salt and pepper
4. Colloid: e.g. milk

Question 16

Q: What is a physical change?

Answer 16

A: A change where the substance remains similar to the starting materials.

Question 17

Q: How is matter described?

Answer 17

A: Using properties.

Question 18

Q: What are physical properties?

Answer 18

A: The look and feel of a substance.

Question 19

Q: What are examples of qualitative physical properties?

Answer 19

A: Colour, texture, state of matter, taste, and smell (not in a lab).

Question 20

Q: How are qualitative physical properties useful?

Answer 20

A: Often used to compare substances
e.g. water and vinegar
- both are liquids
- transparent
- different tastes

Question 21

Q: What is a solution in terms of mixtures?

Answer 21

A: A mixture where you can only see one thing (clear).

Question 22

Q: What is a suspension?

Answer 22

A: A mixture where two parts are stacked on top of each other.

Question 23

Q: What is a mechanical mixture?

Answer 23

A: two parts are all mixed up

Question 24

Q: What is a colloid?

Answer 24

A: A mixture that appears cloudy but only shows one thing.

Question 25

Q: What does homogeneous mean?

Answer 25

A: see only one thing

Question 26

Q: What does heterogeneous mean?

Answer 26

A: see more than one thing

Question 27

Q: What does malleable mean?

Answer 27

A: can change its shape.

Question 28

Q: What does ductile mean?

Answer 28

A: can make into long threads.

Question 29

Q: How do physical properties describe matter?

Answer 29

A: By its appearance (e.g., colour, state, texture).

Question 30

Q: What are qualitative physical properties?

Answer 30

A: 1. no # value 2. often the same for different substances (e.g., water and vinegar have the same colour and state).

Question 31

Q: What are quantitative physical properties?

Answer 31

A: 1. Properties like boiling point, volume, and density give a # value. 2. They vary by substance (e.g., different boiling points for water and vinegar).

Question 32

Q: What is density?

Answer 32

A: The amount of mass in a given volume. It depends on the number of particles in a space.

Question 33

Q: Why is density useful?

Answer 33

A: No two substances have the exact same density, making it a great property for comparison.

Question 34

Q: Equations for density, mass, & volume?

Answer 34

A: 1. Density = Mass ÷ Volume (D = m ÷ V) 2. Mass = Density × Volume (m = D × V). 3. Volume = Mass ÷ Density (V = m ÷ D).

Question 35

Q: What are the units for density?

Answer 35

A: * Liquids: g/mL * Solids/Gases: g/cm³

Question 36

Q: What are the units for mass & volume?

Answer 36

A: * m: g * v: liquid - mL | solid/gas - cm³

Question 37

Q: What is the “magic triangle” for density calculations?

Answer 37

A: A triangle diagram with mass (m) at the top and density (D) and volume (V) at the bottom to help rearrange the formula.

Question 38

Q: What do chemical properties describe?

Answer 38

A: How a substance reacts with something to form something new.

Question 39

Q: What is a chemical change? Provide examples.

Answer 39

A: A chemical change occurs when the new substance is very different from the starting substances. Examples: * Sodium reacts with chlorine gas to make salt. * Iron reacts with air (oxygen + water) to form rust.

Question 40

Q: What are the 5 pieces of evidence of a chemical change?

Answer 40

A: 1. Colour change 2. Bubbles form 3. Heat is made 4. Change of state (gas, liquid, solid) 5. Precipitate forms (tiny pieces drop to the bottom)

Question 41

Q: What did Mendeleev do?

Answer 41

A: Designed the earliest periodic table by organizing elements based on similar properties.

Question 42

Q: What information is found in each square of the periodic table?

Answer 42

A: Atomic number, element name, symbol, and atomic mass.

Question 43

Q: What are the rules for writing element symbols?

Answer 43

A: - Use one or two letters. * The first letter is capitalized, the second (if present) is lowercase.

Question 44

Q: Why are element symbols useful?

Answer 44

A: They are short, universal, and overcome language barriers.

Question 45

Q: what are the 3 main groups of the P.T?

Answer 45

A: 1. Metals (most) - very different properties 2. Non-metals (few) - very different properties 3. Metalloids (staircase) - mixture of properties

Question 46

Q: What are the three subatomic particles?

Answer 46

A: Protons, neutrons, and electrons

Question 47

Q: atomic #

Answer 47

of protons (+)

Question 48

Q: Since atoms are neutral, what will the number of electrons equal?

Answer 48

A: The number of protons.

Question 49

of neutrons

Answer 49

calculate to find out how many but usually close to/same as # of protons

Question 50

Q: What is the maximum number of electrons per shell?

Answer 50

A: 1st = 2 2nd = 8 3rd = 18 depends on the # of shells

Question 51

Q: How does the valence shell affect an atom’s reactivity?

Answer 51

A: 1. If the valence shell is full, the atom does not react. 2. The closer the valence shell is to being full or empty, the more reactive the atom is.

Question 52

ISOTOPES

Answer 52

Atoms of the same element with different amounts of neutrons

Question 53

Formula to find # of NEUTRONS when mass # is given and when it is not given.

Answer 53

1. Mass # - Atomic # = # of NEUTRONS 2. Atomic mass - Atomic # = # of NEUTRONS