Chemical Changes

Question 1

Draw the chemistry tree

Answer 1

Refer to science book

Question 2

What are elements? Give an example.

Answer 2

Pure substances containing ONE type of atom joined together, e.g. O2, H2

Question 3

What can elements be seperated into?

Answer 3

Metals and non- metals

Question 4

What is a chemical symbol? Give an example.

Answer 4

An abbreviation of an element’s name, e.g. Carbon (C), Oxygen (O) Sodium (Na).

Question 5

What are compounds? Give an example.

Answer 5

Pure substances contaning two or more different elements joined together, e.g. CO2, H2O

Question 6

Give examples of common compounds.

Answer 6

Water (H2O), Carbon dioxide (CO2), Hydrchloric acid (HCI), Sulfuric acid (H2SO4), Sodium hydroxide (NaOH), Sodium chloride (NaCl)

Question 7

What is the breaking down of compounds into simpler substances called? Give an example.

Answer 7

Decomposition

E.g. Water –> Hydrogen and oxygen (by electrolysis, broken down into checmials by electricity)

Question 8

Who devised the periodic table?

Answer 8

Mendeleev

Question 9

What does an element’s position on the periodic table indicate?

Answer 9

It’s chemical properties.

Question 10

What is the group number and what does it indicate in an element?

Answer 10

The vertical columns of elements and it indicates the number of electrons in the outer electron shell, e.g. Group 2 has 2 outer shell electrons

Question 11

What is the period and what does it indicate in an element?

Answer 11

The horizontal rows of elements and it indicated the number of electron shells, e.g. Period 3 has 3 shells of electrons.

Question 12

Draw and label an atom diagram.

Answer 12

Refer to diagram

Question 13

What is a proton?

Answer 13

A positively charged particle.

Question 14

What is a neutron?

Answer 14

Particles with no electric charge.

Question 15

What is a electron?

Answer 15

A negatively charged particle.

Question 16

What is valency?

Answer 16

The joining power of an atom.

Question 17

What is the atomic number?

Answer 17

The number of protons in an atom.

Question 18

What is the mass number?

Answer 18

The number of protons and neutrons in an atom.

Question 19

What elements does Group 8 of the Periodic Table contain?

Answer 19

Noble gases (colourless, non-reactive gases), e.g. neon, argon.

Question 20

What elements does Group 7 of the Periodic Table contain?

Answer 20

Halogens (reactive, non- metallic elements), e.g. flourine, chlorine.

Question 21

Name some transition metals.

Answer 21

Copper, zinc (commonly used metal elements)

Question 22

Atroms always have equal numbers of… and….

Answer 22

electrons, protons

Question 23

How many electrons can the

• 1st shell fit?
• 2nd shell?
• 3rd shell?
• 4th shell?

Answer 23

1st shell fits 2 electrons
2nd shell fits 8 electrons
3rd shell fits 8 electrons
4th shell fits -2 electrons

Question 24

What is an ion?

Answer 24

A particle with an electrical charge.

When atoms gain or lose electrons, they are called IONS.

Question 25

Name the first 20 elements on the Periodic Table.

Answer 25

Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesiu,, Aluminium, Silicon, Phosphorus, Sulfur, Chlorine, Argon, Potassium, Calcium

Question 26

Give the chemical symbol for the first 20 elements.

Answer 26

H, He, Li, Be, B, C, N, O, Fl, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca

Question 27

What is the chemical symbol for Iron?

Answer 27

Fe

Question 28

What is the chemical symbol for Mercury?

Answer 28

Hg

Question 29

What is the chemical symbol for Copper?

Answer 29

Cu

Question 30

What is the chemical symbol for Zinc?

Answer 30

Zn

Question 31

What is the chemical symbol for Silver?

Answer 31

Ag

Question 32

What is the chemical symbol for Tin?

Answer 32

Sn

Question 33

What is the chemical symbol for Iodine?

Answer 33

I

Question 34

What is the chemical symbol for Platinum?

Answer 34

Pt

Question 35

What is the chemical symbol for Gold?

Answer 35

Au

Question 36

What is the chemical symbol for Lead?

Answer 36

Pb

Question 37

Draw the 'Activity of Metals' valency chart.

Answer 37

Refer to science book :D

Question 38

What are radicals?

Answer 38

Groups of non- metals that behave as a single particle with a single valency.

Question 39

What is the formula and valency for: - Acetate - Bicarbonate - Cyanide - Hydroxide - Nitrate - Carbonate - Sulfate - Phosphate - Sulfite - Chloride

Answer 39

- CH3COO, -1 - HCO3, -1 - CN, -1 - OH, -1 - NO3, -1 - CO3, -2 - SO4, -2 - PO4, -3 - SO3, -2 - Cl, -1

Question 40

What is a cation?

Answer 40

Positive ion

Question 41

What is a anion?

Answer 41

Negative ion