Atoms, elements and compounds Flashcards Preview

IGCSE Chemistry > Atoms, elements and compounds > Flashcards

Flashcards in Atoms, elements and compounds Deck (33)
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1
Q

What is the relative charge of a proton?

A

+1

2
Q

What is the relative charge of a neutron?

A

no charge

3
Q

What is the relative charge of an electron?

A

-1

4
Q

What is the relative mass of a proton?

A

1

5
Q

What is the relative mass of a neutron?

A

1

6
Q

What is the relative mass of an electron?

A

0.00054 (1/2000)

7
Q

What is a proton number?

A

number of protons in the nucleus of an atom

8
Q

What is a nucleon (mass) number?

A

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

9
Q

What are isotopes?

A

atoms of the same element which have the same proton number but a different nucleon number

10
Q

Why do isotopes have the same properties?

A

they have the same number of electrons in their outer shell

11
Q

What are the two types of isotopes?

A

radioactive

non radioactive

12
Q

What is a medical use of radioisotopes?

A

Sterilizing equipment

Cancer treatment

13
Q

What is an industrial use of radioisotopes?

A

Checking for oil leaks in pipelines

14
Q

What is an element?

A

A substance made of one type of atom

15
Q

What is a mixture?

A

substance contains two or more elements or compounds that are not chemically bonded together

16
Q

What is a compound?

A

substance made up of two or more different types of atoms joined together by chemical bonds

17
Q

What is an alloy?

A

a mixture of a metal with other elements

18
Q

How are ions formed?

A

Electron loss/gain

19
Q

What is an ionic bond?

A

Attraction between positive ions and negative ions

20
Q

What is an ion?

A

Electrically charged particle

21
Q

What is an ionic bond between?

A

Metals + non-metals

22
Q

How are ionic bonds formed?

A

Ions transfer electrons from one atom to another

23
Q

An ionic lattice has + & - ions and is held together by

A

strong electrostatic bonds

24
Q

What are 4 properties of ionic compounds?

A

High fixed points
Poor conductors as solid
Hard
Soluble​ in water

25
Q

Why do ionic compounds have high fixed points?

A

(ionic bonds strong​)

◆ Lots of energy required to overcome electrostatic attraction

26
Q

Why are ionic compounds poor conductors as solids?

A

no moving/free electrons

27
Q

Why are ionic compounds good conductors as liquids?

A

Conducts electricity as liquid (charged ions​ free​ to move)

28
Q

When is a covalent bond formed?

A

when atoms share a pair of electrons

29
Q

What is an covalent bond between?

A

Non-metals + Non-metals

30
Q

What are molecules?

A

a group of atoms held together by COVALENT​ bonds

31
Q

What are 3 properties of covalent compounds?

A

Low fixed points
Do not conduct electricity
Insoluble in water, but dissolve in organic solvents

32
Q

Why don’t covalent compounds conduct electricity?

A

atoms not charged

33
Q

Why do covalent compounds have low fixed points?

A

the weak intermolecular attractive forces