Matter & Chemical Change

Question 1

What is the Law of Conservation of Mass?

Answer 1

• Matter is not created or destroyed, only rearranged
• The total mass of the products must be equal to the total mass of the reactants
• Discovered by Antoine Laurent Lavoisier

Question 2

What’s the difference between exothermic and endothermic reactions?

Answer 2

Exothermic (exiting) reactions release energy while endothermic (enters) reactions require or absorb energy

Question 3

What does a manipulated variable means in an experiment?

Answer 3

The variable that is changed

Question 4

What are the four factors that can increase a chemical reaction?

Answer 4

Change the temperature (heat up) Add a catalyst (enzyme) Increase the surface area (break into smaller pieces) Increase the concentration (amount) of reactants

Question 5

What are the three types of reactions with oxygen?

Answer 5

Combustion: when oxygen and another substance react together to produce a new substance and energy Corrosion: when oxygen in the atmosphere reacts with a metal producing rust Cellular Respiration: breathing of your cells

Question 6

What kind of air conditions has the lowest moisture? (What kind of air conditions would make corrosion [rust] occur slower?)

Answer 6

Cold and dry

Question 7

What’s the difference between a physical and chemical change?

Answer 7

A physical change is a change in appearance or state of a substance [particles stay the same], while a chemical change is when a new substance is made

Question 8

What’s the difference between reactants and products in a chemical reaction?

Answer 8

Products is what is produced from the reaction, the reactants are the substances that react together to make the product.

Question 9

Where do you find the charges on an element in the periodic table?

Answer 9

Found at the top right corner of an element

Question 10

Be able to read a word equation

Answer 10

Test will take the word sentence and break it down smaller. Ex.

Question 11

Metal + Non-metal = ________

Answer 11

Ionic compound

Question 12

Non-metal + Non-metal = ________

Answer 12

Molecular compound

Question 13

What’s the Roman Numeral means on an ionic compound

Answer 13

If more than one charge on metal, tells you the charge you’re using

Question 14

How do you calculate the number of neutrons in an element?

Answer 14

Subtract the atomic number from the mass number

Question 15

Where are metals and non-metals found on a periodic table?

Answer 15

Left of staircase: Metals On Staircase: Metalloid Right of staircase: Non-metals

Question 16

What are the four indicators of a chemical change?

Answer 16

-Change in odour -Heat release/absorption -Formation of gas or solid\ -Change in colour

Question 17

What is the most recent theory of matter is and what does it say?

Answer 17

Quantum Mechanics: the electrons are in a cloud around the nucleus (moving all around)

Question 18

Know the structure of an atom and how to compare it to a solar system

Answer 18

The Sun= nucleus (protons & neutrons) The Planets= electrons

Question 19

Be able to pick out some examples of a pure substance Ex. ‘water’ or ‘distilled water’ -> Mixture or pure substance? Ex. ‘air’ -> Mixture or pure substance?

Answer 19

Pure substances are elements or compounds Ex. They say ‘water’ and ‘distilled water’ The distilled (filtered) water is the pure substance because if its just water, it could have particles of dirt in it. The water is a mixture. Ex. They say ‘air’ It’s not a pure substance because it could have dust, skin particles. It’s a mixture.

Question 20

What do you do immediately do should you come in contact with a harmful chemical during a science experiment?

Answer 20

Wash it immediately, then seek help.

Question 21

How do you name ionic compounds? Ex: NaCL

Answer 21

1. Write down the name of the metal ion first – Sodium 2. Write down the name of the non-metal ion second but change the ending to “ide” – Chloride 3. Therefore NaCl = Sodium Chloride * Sometimes a metal ion has more than one charge so you need to use Roman numerals to indicate the one you are using. Example: Copper(II) Chloride has copper with a 2+

Question 22

How do you write an ionic formula? Ex: Magnesium Chloride

Answer 22

1. Write down metal ion first with its charge – Mg2+ 2. Write down the non-metal ion next with its charge – Mg2+Cl- 3. Keep adding either metal or non-metal ions until the charges balance. They must equal zero – Mg2+Cl-Cl- 4. Count the number of ions of each element and put the number as a subscript to the right of the ion symbol and remove the charge. Remember the number 1 is invisible 5. Therefore Mg2+Cl-Cl- = MgCl2

Question 23

How do you name molecular compounds? Ex: OCl2

Answer 23

1. Write down the element name for the first element – Oxygen 2. If there is more than one atom of an element, you need to add the appropriate prefix (tri, penta, etc.) 3. Write the name of the second element with the “ide” ending and include the prefix – dichloride 4. Therefore OCl2 = Oxygen dichloride

Question 24

Name the 10 prefixes for molecular compounds

Answer 24

MDTTPHHOND [maggie’s dad tried to put his hairy opening near daryl] Mono (don’t use for first element) Di Tri Tetra Penta Hexa Octa Nona Deca

Question 25

How do you write a formula for molecular compounds? Ex: Dinitrogen Tetraoxide

Answer 25

1. Turn the element names into symbols – N O 2. Add the prefixes as subscripts – N2O4 3. Therefore Dinitrogen Tetraoxide = N2O4

Question 26

What’s the difference between family/groups and periods/orbits and what is the characteristics that elements have in each?

Answer 26

The horizontal rows are called periods or orbits: The characteristics of the elements in a period or group change as you go left to right. Also the atomic mass increases as you go left to right The vertical columns are called families or groups: The elements in a family or group tend to have similar characteristics

Question 27

How do you calculate the number of protons and electrons in an element?

Answer 27

Both are found by the atomic number Ex: Atomic Number = 13 So, Electrons: 13 Protons: 13

Question 28

Identify the 8 WHMIS symbols

Answer 28

WHMIS Symbols with Names