Atoms

Question 1

Atom definition

Answer 1

The smallest particle that can be obtained by chemical means

Question 2

1 nanometer(nm)

Answer 2

10^-9 m

Question 3

Element

Answer 3

Cannot be broken down into simpler substances by chemical means and contains only one type of atom

Question 4

Compound

Answer 4

A substance made by chemically combining two or more elements

Question 5

Synthesis

Answer 5

The building up of more complex substances by chemically combining two or more elements

Question 6

Decomposition

Answer 6

The breaking down of more complex substances into simpler ones

Question 7

Molecule

Answer 7

Consists of two or more atoms joined together by chemical bonds

Question 8

Ion

Answer 8

A particle with an electric charge to it

Question 9

Atomic number

Answer 9

Number of protons

Question 10

Mass number

Answer 10

Number of protons + number of neutrons

Question 11

Number of electrons

Answer 11

Mass number - number of protons

Question 12

Isotopes

Answer 12

Atoms of the same element with the same number of protons but different number of neutrons

Question 13

Ionic bond

Answer 13

The electrostatic attraction between two ions of opposite charges

Question 14

Ionic compounds

Answer 14

The product of a reaction between metals and non-metals

Question 15

Covalent bond

Answer 15

When 2 atoms share one or more pairs of electrons

Question 16

Compound ion

Answer 16

Group of different atoms joined together which overall have a charge

Question 17

Smallest atom

Answer 17

Hydrogen

Question 18

The element with 118 protons

Answer 18

Uuo, eka-radon, element 118

Question 19

By who and when was the structure of the atom discovered

Answer 19

In 1910, Ernest Rutherford discovered that an atom consists of a nucleus and a cloud of electrons

Question 20

By who and when were chemical symbols introduced

Answer 20

Jons Berzelius in 1811

Question 21

What characteristics do all elements have?

Answer 21

Melting point
Boiling point
Density
Chemical properties

Question 22

Why do elements have different properties?

Answer 22

Because they have different atoms

Question 23

What are the characteristics of chlorine

Answer 23

Green, toxic gas

Question 24

What are the characteristics of sodium?

Answer 24

Soft, flammable metal

Question 25

What ions do metals form

Answer 25

Positive

Question 26

What ions do non-metals form

Answer 26

Negative

Question 27

A.M.U

Answer 27

Atomic mass unit

Question 28

Mass of electron

Answer 28

1/1850 the mass of a proton

Question 29

Who proposed the idea of electron shells?

Answer 29

Niel Bohr. He proposed the idea that electrons circle around the nucleus of an atom at different energy levels (electron shells)

Question 30

How do we describe a nucleus with extra neutrons?

Answer 30

Unstable. Isotopes.

Question 31

What will happen to an isotope?

Answer 31

It will decay quickly.

Question 32

What is a radioisotope?

Answer 32

An isotope that gives out radiation when it decays

Question 33

Carbon dating

Answer 33

By knowing how long it takes for half of the carbon-14 atoms to decay (=half-life), we can know the age of a fragment of wood, bone or cloth.

Question 34

What is a covalent bond between?

Answer 34

2 non-metals

Question 34

Indicator

Answer 34

A substance which changes color depending on if it is mixed with an acid or alkali

Question 34

What color do acids turn litmus solution and blue litmus paper

Answer 34

Red

Question 34

Examples of acids

Answer 34

Citric (oranges, lemons) Tannic (tea) Ethanoic (vinegar) Methanoic (nettle stings) Carbonic acid (fizzy drinks)

Question 35

What is carbonic acid (formula)

Answer 35

CO2 + H2O = H2CO3

Question 36

Sodium hydroxide

Answer 36

NaOH

Question 37

Potassium hydroxide

Answer 37

KOH

Question 38

Calcium hydroxide

Answer 38

Ca(OH)2

Question 39

Ammonia solution

Answer 39

NH3

Question 40

What color do alkalis turn litmus solution and red litmus paper

Answer 40

Blue

Question 41

pH scale

Answer 41

Measures the strength of an acid or alkali

Question 42

How much more acidic is a pH 3 solution than a pH 4 one?

Answer 42

x10 more acidic

Question 43

How much more acidic is a pH 3 solution than a pH 5 one?

Answer 43

x100 more acidic

Question 44

What does an acid + alkali form?

Answer 44

Salt + water

Question 45

What does HCl + NaOH form?

Answer 45

NaCl + H2O

Question 46

What does Mg + H2SO4 form?

Answer 46

MgSO4 + H2

Question 47

What does CaCO3 + HCl form?

Answer 47

CaCl2 + CO2 + H2O

Question 48

What alkalis do kitchen cleaners contain?

Answer 48

Sodium hydroxide or ammonia

Question 49

Limescale

Answer 49

Calcium carbonate

Question 50

What can bee stings be neutralized by?

Answer 50

Calamine lotion, baking soda

Question 51

What can wasp stings be neutralized by?

Answer 51

Vinegar, lemon juice

Question 52

What acid do we produce?

Answer 52

Hydrochloric acid

Question 53

How to fix indigestion

Answer 53

Baking soda, indigestion tablet

Question 54

Why does toothpaste contain alkalis

Answer 54

Our mouths produce acid which if goes below a pH of 5.5, the acid will start to dissolve the enamel

Question 55

What is acidic soil treated with?

Answer 55

Quicklime (calcium oxide), slaked lime (calcium hydroxide), chalk (calcium carbonate)