Acids And Bases

Question 1

The amount of basic atoms are:

Answer 1

118

Question 2

Lustrous

Answer 2

They shine when polished

Question 3

Malleable

Answer 3

They can be bent into new shapes without breaking

Question 4

Ductile

Answer 4

Can be stretched into wires

Question 5

Element cannot

Answer 5

Be broken down into more fundamental substances

Question 6

There are ____ known elements arranged in order of their atomic number

Answer 6

118

Question 7

___ atoms are made in the

Answer 7

20, laboratory

Question 8

—- types of atoms are found naturally on earth

Answer 8

98

Question 9

Crystal lattices

Answer 9

Are grid like structures (sio2)

Question 10

Element is a substance whose atoms all

Answer 10

have the same number of protons: element’s atoms have the same atomic number

Question 11

Compound

Answer 11

A substance that results from a combination of two or more different chemical events. They are held together by chemical bonds that are difficult to break

Question 12

Mixture

Answer 12

Composed of two or more seperate elements

Question 13

Inside atoms

Answer 13

Atoms are made up of even smaller particles known as subatomic particles

Question 14

Electrostatic attraction

Answer 14

Negative charge of electrons causes them to be attracted to the positively charged protons

Question 15

Repulsion

Answer 15

Opposite charges (+/-) attract each other like charges (+/+) (-/-) repel each other

Question 16

Electron cloud

Answer 16

Used to describe where electrons are when they go around the nucleus of an atom

Question 17

Neutron

Answer 17

It is a subatomic particle (smaller than or occurring within an atom). Neutrons have zero change = are neutral particles (not supporting // no strong features)

Question 18

Proton

Answer 18

Electrically charged. Relative charged of +1. The number of protons is an atom is called its atomic number

Question 19

Nucleus

Answer 19

Is a small, dense region consisting of protons and neutrons at the centre of an atom

Question 20

Atomic number and mass number

Answer 20

Number if protons in the nucleus determines the type of atom it is and what element it belongs to. All atoms of a particular elect have the same atomic number (number of protons). E.g. gold atoms contain 79 protons. Number of neutrons affect the atom’s mass. Number if protons + neutrons = mass number. And mass number - atomic number = number of neutrons

Question 21

Electrons and the nucleus

Answer 21

The number of electrons surrounding the nucleus of an atom is exactly equal to the number of protons in the nucleus. Atoms have no electric charge (charge neutral)

Question 22

Alloy

Answer 22

Is known as a base metal. Combined with small amounts of other elements. (Defined by a metal bonding character)

Question 23

Metals are

Answer 23

Dense
Electrical conductors
Malleable
Most metals are solid at room temperature
Ductile (stretch and drawn into thin wires)
Lustrous (shine when polished/freshly cut)
Are thermal conductors (pass heat easily along/through)

Question 24

Ions

Answer 24

Atoms can lose/gain electrons to become electrically charged particles called ions (formed as a cation). Ions has non-zero net electrical charge cation - positively/anion - negatively changed

Question 25

Metalloids

Answer 25

Any chemical element which has properties between. Those of metals and non-metals or a mixture. Metalloids are semi conductors (conduct electricity under certain conditions)

Question 26

Non-metals

Answer 26

Most non-metals are found naturally as gases in the air. (Sulfur in volcanoes) a few solids round in the earths crudh

Question 27

Carbon

Answer 27

Pure carbon exists in several different forms called; allotropes Amorphous carbon Diamond Graphite

Question 28

Acid

Answer 28

An acid is a substance that releases hydrogen ions (H+) in an aqueous solution ( in gaining water)

Question 29

Properties of acids are:

Answer 29

``` Corrosive Sour taste Turn blue litmus paper red React with some metals, releasing hydrogen gas and leaving salt behind Contact electicity Neutralised by bases ```

Question 30

Bases and alkalis

Answer 30

``` Releases hydroxide ion (Oh-) (eg (naOH)s) Are caustic (ability to burn) Have a soapy, slimy feel Turn red litmus paper blue Butter taste Conduct electricity Neutralise acids ```

Question 31

Use a weak base for things such as;

Answer 31

Soap and toothpaste - when a base can be dissolved in water, it is known as alkali - the solution it forms is called alkaline solution - all bases have similar chemical properties

Question 32

The strength of an acid depends on

Answer 32

How many hydrogen ions are released. (An acid is weak if only a few of its molecules release hydrogen ions)

Question 33

A base is a substance that release hydroxide ions

Answer 33

(oH-)

Question 34

Neutral on a pH scale is

Answer 34

7

Question 35

7 (neutral) on a pH scale is

Answer 35

Distilled water

Question 36

Measuring pH

Answer 36

Indicators are chemical that’s change colour to show whether a substance is acidic, neutral or basic. A common indicator is litmus paper.

Question 37

Another way of measuring pH is to use

Answer 37

A pH meter

Question 38

Allotropes

Answer 38

Different forms of the same element

Question 39

Anion

Answer 39

An ion that has more electrons than protons and is negatively charged

Question 40

Atomic number

Answer 40

The number of protons in the nucleus; the atomic number determines what type of atom it is

Question 41

Base

Answer 41

A substance that releases hydroxide ions

Question 42

Cation

Answer 42

An ion that has fewer electrons than protons and is positively charged

Question 43

Mass number

Answer 43

The number of protons and neutrons in an atom