Atoms elements compounds

Question 1

What’s the relative mass of Protons neutrons and electrons?

Answer 1

Proton: 1
Neutron: 1
Electron: 0 (1/1836)

Question 2

what are the relative charges of protons neutrons and electrons

Answer 2

Protons: +1
Neutrons: 0
Electrons: -1

Question 3

Why do Atoms contain equal numbers of protons and electrons?

Answer 3

Atoms are stable with no Overall charge
Protons have a relative charge of -1 so there must be an equal number for the charges to balance.

Question 4

what does atomic number represent?

Answer 4

The number of Protons in an atomic nucleus.

Question 5

what does the mass number of an atom mean

Answer 5

the total number of protons and neutrons found in the nucleus of an atom

Question 6

how are elements arranged in the periodic table?

Answer 6

in order of increasing atomic number. Elements with similar properties are in the same group

Question 7

why do elements in the same group have similar properties?

Answer 7

Elements in the same group have the same number of electrons in the outer shell which determines how they react.

Question 8

what does the periodic (row) number tell you about elements in that period?

Answer 8

They all have the same number of electron Shells e.g all elements in period 4 have 4 shells of electrons

Question 9

what are isotopes?

Answer 9

Atoms of an elements with the same number of protons but a different number of nuetrons.
Isotopes of an element have the same atomic number but different atomic mass

Question 10

why do isotopes have the same properties? (extended only)

Answer 10

because they have the same number of electron in their outer shell so they react in the same way.

Question 11

what are the two types of isotope?

Answer 11

radioactive and non-reactive

Question 12

medical use of isotopes

Answer 12

Tracers
Cancer treatment
Lung and organ imaging
Anemia diagnosis

Question 13

Industrial use of isotopes

Answer 13

smoke alarms
Tracer (to find leaks in pipes for example)
sterilisation

Question 14

how are electrons arraigned in an atom?

Answer 14

in shells around the nucleus
the maximum number of electrons in the first 3 shells is 2,8,8 the first shell can hold 2 electrons and the second and third can hold 8

Question 15

what is the most stable electron configuration?

Answer 15

the full outer shell of electrons
for the first shells this is either (2), (2,8) or (2,8,8)
Atoms react in order to gain a full outer shell so that they become more stable

Question 16

which group are the noble gasses in the periodic table?

Answer 16

Group 8
Known sometimes as Group Zero

Question 17

why are the noble gasses very unreactive?

Answer 17

the noble gassed all have a full outer shell meaning they already have the most stable electron configuration. As a result, they do not react easily.

Question 18

what is the difference between an element and a compound?

Answer 18

An element is a substance made up of only one type of atom whereas a compound is made up of two or more chemically combined elements

Question 19

what is a mixture?

Answer 19

contains 2 or more elements/compounds which are not chemically combined.

Question 20

what is a metal and where are they found in the periodic table?

Answer 20

Metals are found towards the left and bottom of the table.
Metals lose electrons to form positive ions.

Question 21

what is a non metal and where are they found in the periodic table

Answer 21

non metals are found towards the top right of the periodic table
non metals gain electrons to form negative ions

Question 22

what is an alloy?

Answer 22

A mixture containing a metal and another element ( could be a different metal or a non metal)

Question 23

why are alloys harder than pure metals?

Answer 23

Atoms in pure metals are arranged in uniform rows which can easily slide over each other, making them very malleable.
Alloys contain different sized atoms which distort these lavers meaning the layers are unable to slide, increasing the hardness of the material.

Question 24

what is a brass? what is it used for?

Answer 24

Brass is an alloy of copper and zinc
Brass is hard and resistant to corrosion so it can be used for decorative hardware like plumping fittings

Question 25

what are ions?

Answer 25

positively/negatively charged atoms

Question 26

how are ions formed?

Answer 26

Positive ions form when an atom loses electrons
Negative ions form when an atom gains electrons.

Question 27

what are cations and anions?

Answer 27

Cation - Positive Ion
Anion - Negative Ion

Question 28

How are Ionic bonds formed between group 1 and 7 elements

Answer 28

Group I elements lose their only outer shell electron to form 1+ ions. Group VIl elements have seven electrons in their outer shell and can gain the electron lost from the group 1 element to form ions with a 1- charge.
An ionic bond can form between these oppositely charged ions.

Question 29

What types of elements add ionic bonds formed between? Ext

Answer 29

lonic bonds form between metals and non-metals.
Metal lose electrons to form positive ions.
Non-metals gain electrons to become negative ions.

Question 30

Describe Structure of an ionic compound

Answer 30

• Giant lattice structure.
• Regular alternating arrangement of positive and negative ions.
• Held together by electrostatic attraction between oppositely charged ions.

Question 31

What’s a covalent bond?

Answer 31

A bond formed when two non metals share a pair of electrons

Question 32

why do atoms form covalent bonds

Answer 32

to obtain more stable electron configuration

Question 33

Give an example of a compound that contains atleast 1 covalent bond

Answer 33

Hydrogen Chlorine Water Methane Ammonie Hydrochloric acid

Question 34

Explain formation of the covalent bonds in carbon dioxide CO2

Answer 34

Carbon has the electron configuration (2, 4) and oxygen has the electron configuration (2, 6).
The carbon atom forms a double covalent bond with each oxygen atom. This means each oxygen shares two pairs of electrons with the carbon. In total, the carbon will gain 4 electrons as it shares by a total of four electron pairs.

Question 35

Explain the formation of covalent bonds in nitrogen

Answer 35

A nitrogen atom has the electron configuration (2, 5).
A triple covalent bond forms between the nitrogen atoms with three pairs of electrons shared between them.