Chem 4

Question 1

What is the structure of an atom

Answer 1

an extremely small, positively charged nucleus surrounded by a cloud of negatively charged electrons

Question 2

How are elements ordered on the periodic table

Answer 2

in order of increasing atomic number.

Question 3

What are the horizontal rows on the periodic table called

Answer 3

Periods

Question 4

What are the vertical columns on the periodic table called

Answer 4

Groups

Question 5

Why are te elements in the periodic table grouped in the way they are

Answer 5

Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.

Question 6

Valency definition

Answer 6

Valency is the combining power of an element The valency of an element is related to how many electrons are in the outer shell.

Question 7

Oxidation definition

Answer 7

A chemical reaction that takes place when a substance comes into contact with oxygen or another oxidizing substance. Examples of oxidation are rust and the brown color on a cut apple.

Question 8

Reduction def

Answer 8

the gain of electrons, loss of oxygen, or gain of hydrogen

Question 9

What is the reactivity series used for

Answer 9

to predict whether a metal can displace another in a single displacement reaction

Question 10

The reactivity series was created by

Answer 10

using the observations of their reactions with oxygen, water and acid

Question 11

What’s an exothermic reaction

Answer 11

a chemical reaction that releases energy by light or heat

Question 12

What’s an endothermic reaction

Answer 12

chemical reactions in which the reactants absorb heat energy from the surroundings to form products

Question 13

Group one elements are

Answer 13

soft, reactive metals with low melting points

Question 14

Group two elements are

Answer 14

shiny, silvery-white in appearance, and possess relatively low densities

Question 15

Group 3 on periodic table is

Answer 15

soft, silvery-white metals

Question 16

Group 4 on periodic tables

Answer 16

hard, refractory metals

Question 17

Group 5 on periodic table is

Answer 17

. Niobium has the largest known magnetic penetration depth of all the elements

Question 18

G 7 on periodic table is

Answer 18

As you go down the halogens, from fluorine to astatine, the elements become darker in colour and have a higher boiling point

Question 19

Common properties of metals are

Answer 19

malleable, ductile, good conductors of heat and electricity

Question 20

Common properties of non metal are

Answer 20

bad conductors of heat and electricity (except graphite, may be solids, liquids or gases at room temperature

Question 21

Polymers properties

Answer 21

tensile strength, durability, viscoelasticity, reactivity, melting point, conductivity

Question 22

Uses of polymers

Answer 22

clothing made from synthetic fibers, polyethylene cups, fiberglass, nylon bearings, plastic bags,

Question 23

Describe how carbon can be used to extract certain metals from their ores

Answer 23

by heating with carbon

Question 24

How does the energy of particles Change as the change state

Answer 24

As heat energy is added, the particles gain more heat energy until they undergo the process of changing state, at which point their temperature remains constant.

Question 25

F

Answer 25

Measure out 10 cm3 of hydrochloric acid and carefully add this to the sodium hydroxide solution in the polystyrene cup. Stir with the thermometer and record the maximum or minimum temperature reached. Work out the temperature change and decide if the reaction is exothermic or endothermic