MP2Q Study Guide

Chemistry

1. Describe a Physical change and give 3 examples

• A change that affect one or more physical properties of a substance but does not change the identity of the substance

• Freeze water, break a pencil, crush a can, melt an ice pop, sand wood

2.Describe a chemical change and give 3 examples

• When one or more substances are changed into new substances with different properties

• Nail rusts, bake a cake, milk sours, wood burns

3. How can you tell the difference between a physical and chemical change?

• If a physical change happens, you still have the same substance but in a different form

• If a chemical change happens, a new substance is formed with different properties

4. List 4 signs of a chemical change

• Fizzing and foaming, gas formation• Change in color or odor• Light or sound given off• Production of heat (energy)• Solid formation(precipitate)

Physical vs. Chemical properties

5. Four examples of physical properties of matter

• Soluble• Ductile• Malleable• Thermal conductivity• Color• Texture• Mass• Volume• density

6. Two examples of chemical properties

• Flammability• Reactivity

7. What does the Law of Conservation of Matter state?

• Matter cannot be created or destroyed in ordinary chemical and physical changes

Describe the particle movement of…

8. gas: particles move very fast and far apart9. liquid: particles slide back and forth on one another10. Solid: close together and vibrate in place

11. What is a compound and how can it be separated? Give an example.

• A pure substance made of two or more elements that are chemically combined

• The only way to separate a compound is through a chemical change

• Examples: salt, NaCl water, H2O carbon dioxide, CO2

12. What is a mixture and how can it be separated? Give an example.

• A combination of two or more substances not chemically combined

• Mixtures can be separated by physical meansusing distillation, using a magnet, or a centrifuge

Examples: granite, pizza toppings, salad

13. Five scientists who helped develop the atomic theory…

Democritus: an atom was a small, hard particle that was unable to be dividedJohn Dalton: Published the atomic theory• All substances are made of atoms• Atoms join together to make new substances• Atoms of the same element are the same,

atoms of different elements are different

JJ Thomson: discovered negatively charged particles called electrons, plum-pudding model

Niels Bohr: electrons travel in certain paths called energy levels

Ernest Rutherford: there is a positively charged nucleus with electrons traveling around it

14. The word atom from the Greek “atomos” means…

…unable to be divided.

15. Describe the location of the metals, nonmetals, and metalloids. Which is the largest group?

• Metals are to the left of the zigzag line• Nonmetals are to the right of the zigzag line

• Metalloids are along the zigzag line

16.How did Mendeleev arrange the elements on the periodic table?

The elements are arranged according to increasing atomic mass.

17. What holds atoms together?

…forces called chemical bonds

18. How many atoms of oxygen are in ….

C6H12O6 six

H2O2 two

H2SO4 four

19. How many atoms are in the formula?

Mg3N2 5

C6H12O6 24

H2SO4 7

20. The three subatomic particles are…

• Electrons which are negatively charged• Protons which are positively charged• Neutrons which have no charge

Electrons are the smallest

21. What is the mass number?

The mass number is equal to the sum of protons + neutronsAtomic mass= p + n

22. Bohr model of Lithium

23. Properties of metals, nonmetals and metalloids

Metals

• Shiny• Ductile• Malleable• Good conductors of heat

and electricity

Metalloids share properties of both metals and nonmetals

Nonmetals• Dull• Not malleable• Not ductile• Brittle• Poor conductors of heat

and electricity

Sulphur