Chemistry

Question 1

list 3 of the particles that make up an atom

Answer 1

Protons
Neutrons
Electrons

Question 2

What are the 3 particles charges of an atom

Answer 2

Protons-Positive
Neutrons- Neutral
Electrons- Negative

Question 3

Using an example explain the difference between reactants and products in a chemical equation.

Answer 3

Hydrogen + Oxygen= Water

     Reactants            Product

Question 4

State the Law of Conservation of Mass

Answer 4

In a chemical reaction, the total mass of the reactants is the same as the total mass of the products. Also mass throughout a chemical reaction cannot be created or destroyed.

Question 5

Is the mass of the reactants the same as the mass of the products in a chemical equation? Explain your answer.

Answer 5

The mass of the products is equal to the mass of the reactants because of the law of conservation of mass

Question 6

What is an isotope? Give an example.

Answer 6

An isotope is an atom that has the same atomic number but a different atomic mass

E.g 12/6 C and 13/6 C. Carbon 13 has one more neutron than carbon 12

Question 7

What is an exothermic reaction? Give an example.

Answer 7

Gives of heat

E.g Burning magnesium

Question 8

What is the difference between an acid and a base? Give an example of each.

Answer 8

An acid contains a high amount of hydrogen ions.

E.g HCl and H2SO4

A base contains a large number of hydroxide ions

E.g NaOH and KoH

Question 9

What is a Neutralisation reaction? Give an example.

Answer 9

Acid + base –> Salt and Water

HCl+ NaOH –> NaCl + H2O

Question 10

What are the products of an acid/base reaction?

Answer 10

Products are always an ionic salt and water

Question 11

What are valence electrons

Answer 11

The electrons in the outermost shell of an atom

Question 12

How does an atom form an ion?

Answer 12

When an atom loses or gains an electron it forms an ion

Question 13

What is the difference between a cation and an anion? Give an example of each.

Answer 13

Cantions are positive ions
E.g Na+

Anions are negative ions
E.g N3-, Cl-

Question 14

What ions does Sodium form

Answer 14

Na+

Question 15

What ions does Magnesium form

Answer 15

Mg2+

Question 16

What ions does Aluminium form

Answer 16

Al3+

Question 17

What ions does Fluorine form

Answer 17

F-

Question 18

What ions does Argon form

Answer 18

Ar (no charge )

Question 19

What ions does Sulfure form

Answer 19

S2-

Question 20

What ions does Oxygen form

Answer 20

O2-

Question 21

If calcium and chlorine join together, what is the chemical formula?

Answer 21

Calcium + chlorine –> Calcium Chloride

2Ca + O2 –> 2CaO

Question 22

Write a balanced chemical equation for when magnesium burns in oxygen.

Answer 22

2Mg + O2 –> 2MgO

Question 23

Why is this chemical formula incorrect Mg2N3? What should it be?

Answer 23

The 2 and the 3 should be swapped. The 2 is a positive and the 3 is a negative.

Question 24

For the atomic symbol of gold 197/79 A, what do the 197 and 79 numbers represent?

Answer 24

197 is the Atomic mass and the 79 is the Atomic number

Question 25

Give an example of a combustion reaction

Answer 25

The burning of magnesium or any other substance

Question 26

What is an Endothermic reaction and give an example

Answer 26

Absorbs heat and an example if making an ice cube.

Question 27

Describe the earliest model of the atom

Answer 27

The plum pudding model was devised by J.J Thomson and it showed negatively charged electrons embedded in a positively charged sphere.

Question 28

How do you calculate the number of valence electrons?

Answer 28

the number of valence electrons is equal to its main group number, which is the element's column on the periodic table.

Question 29

If an element is in the last column of the periodic table, does it form an ion?

Answer 29

no because it's part of the Nobel gasses group so they are unreactive

Question 30

What is corrosion?

Answer 30

Where metals react with substances in their environment and are gradually destroyed

Question 31

What substance do metals commonly react with during corrosion

Answer 31

oxygen

Question 32

What is the atomic mass?

Answer 32

Number of protons and neutrons

Question 33

What is the atomic number?

Answer 33

number of protons

Question 34

What is an example of metal in an acid reaction

Answer 34

zinc + hydrochloric acid = zinc chloride and hydrogen gas.

Question 35

what is the products of an acid/metal reaction?

Answer 35

a salt and hydrogen gas