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Flashcards in 2nd Year Summer Science Test Deck (75):
1

Name a dangerous acid and give an example

Sulfuric acid in car batteries it is dangerous and corrosive

2

Name two good acids and give an example

Acetic acid = vinegar
Carbonic acid = fizzy drinks

3

What is an indicator

An indicator shows by means of a colour change whether a substance is acidic or basic

4

What colour does litmus paper turn when it is mixed with an acid

It turns from blue to red

5

What is sodium hydroxide and what colour does it change to when mixed with litmus

Sodium hydroxide is a base it turns litmus from red to blue

6

What are alkalis

alkalis are bases that dissolve in water sodium hydroxide is an alkalis dissolves in water very corrosive expressly to skin

7

What does litmus do

Litmus can show whether or not a substance is acidic or basic by colour change

8

What is it called when there is no colour change on the indicator

Natural substances is when there is no colour change on the indicator this means that the substances or nor an acid or base example water salt and sugar

9

What colour does the litmus change with a natural substance

Red litmus stays red blue litmus stays blue

10

What does an indicator show

And indicator shows by means of a colour change whether a substance is acidic or basic

11

How do you indicate the level of acidity or Basicity

In order to indicate the level of acidity or Basicity chemist use a special scale called the pH scale. The scale goes from 0 to 14

12

What is the level of the pH scale

A solution Whose pH is 7 is neutral
A solution whose PH is less than 7 is acidic
A solution whose pH is greater than 7 is alkaline

13

What is pH paper

PH paper is simply universal indicator solution which is been soaked onto paper it is a mixture of indicators

14

How much percent of the air is carbon dioxide

Less than 1% of the air is carbon dioxide

15

When is carbon dioxide produced

Carbon dioxide is produced when carbon is burned in oxygen gas

16

What is the chemical name for marble

Calcium carbonate formula CaCo3

17

What is the word equation between dilute hydrochloric acid and marble chips

Calcium carbonate + hydraulic acid
( dilute)
-> calcium chloride + water + carbon dioxide

18

What is the balance chemical equation for this reaction

CaCo3+ 2Hcl -> CaCl2 + H2O + Co2

19

How is carbon collected

Carbon is collected by the upward displacement of air

20

Name three physical and chemical properties of carbon dioxide

Physical properties Chemical properties.
Colourless orderless tasteless. Does not support combustion
Slightly soluble in water. Turns limewater milky
More dense than air. Dissolves in water carbonic acid

21

What is an atom

And atom is the smallest particle of an element

22

How many different kinds of atoms are there

There are 100 different kinds of atoms

23

What must be used to see an atom

Electron microscope must be used

24

Who put forward the theory about atoms

John dalton

25

What does sub-atomic mean

Sub-atomic means there are particles inside the atom that John was wrong

26

How many particles are in an atom and what are they called

There are three particles inside an atom
protons positive charge
electrons negative charge and
neutrons neutral charge

27

The number of ? and the number of ? are always the same

The number of protons on the number of electrons are always the same

28

What is the special name is given to the number of protons in the nucleus

The number of protons in the nucleus of an atom is given a special name this number is called the atomic number of the atom

29

What is the atomic number of an atom

The atomic number of an atom is the number of protons in the nucleus of that atom

30

Each ? has its own atomic number

Each element has its own atomic number

31

What is the mass number

The mass number is the number of protons + the number of neutrons

32

What is the only element that has no neutrons in its nucleus

Hydrogen is the only element that has no neutrons in its nucleus

33

What do electrons do

Electrons move around the Nucleus in paths Called Orbits or shells

34

What is the periodic table

The periodic table is an arrangement of elements in order of increasing atomic number

35

What are the vertical columns and the horizontal rows called

The vertical columns are called groups
the horizontal rows are called periods

36

What elements appear in the same group of the periodic table

Elements of similar chemical properties appear in the same group of the periodic table

37

What are isotopes

Isotopes are atoms of the same element that have different numbers of neutrons

38

Who was the person first person to draw up the periodic table

Dmitri mendeleev

39

How many main groups are in the periodic table

8

40

What number is always the smaller number

The atomic number

41

What is the chemical formula

A chemical formula shows which elements are present in a compound it also shows how many atoms of each element are present in a molecule of the compound

42

What are the reactions

The reactions are the chemicals that react together in a chemical chemical reaction

43

What are the products

The products are the chemicals that are produced in a chemical reaction

44

What must the chemical equation always be

The chemical equation must always be balanced

45

What are chemical formula is used for

Chemical formula as are used to represent the compound or a molecule of a compound

46

List five covalent compounds

Hydrogen chloride - HCL
water - H2O
methane - CH4
carbon dioxide - CO2
Hydrogen peroxide -H2O2

47

List five ionic compounds

Sodium chloride - NaCL
magnesium oxide - MgO
iron sulfide - FeS
calcium chloride - CaCL2
copper sulfate - CuSo4

48

What are the two types of equations in chemistry

Word equations and chemical equations

49

What is the word equation for hydrogen and oxygen

Hydrogen + oxygen -> water

50

What are the chemicals that react together in a chemical reaction

Hi did Jen and oxygen are the chemicals that react together in the chemical reaction these chemicals are called the reactants

51

What is a balanced word equation

A balance word equation is one in which the total number of atoms of each element on the left hand side of the equation is equal to the total number of atoms on the right hand side of the equation

52

What is a molecule

A molecule is a group of atoms joined together it is the smallest particle of an element or compound that exists independently

53

What is a covalent

A covalent is a bond that consists of shared electrons

54

What is a double bond

A double bond is formed when 2 pairs of electrons are shared

55

What is a single bond

A single bond is when a pair of electrons are shared

56

What is an ionic bond

And ionic bond is the force of attraction between positive and negative ions in a compound

57

What do Ionic compounds consist of

Ionic compounds consist of ions

58

What do covalent compounds consist of

Covalent compounds consist of individual molecules

59

What is an ion

An ion is a charged atom or group of atoms

60

Name four ionic compounds

Solid at room temperature
high melting and boiling points
dissolve in water
conduct electricity

61

Name for covalent compounds

I liquid and a gas at room temperature
low melting and boiling points
many don't dissolve in water
do not conduct electricity

62

What does gravity do

Gravity holds the atmosphere near the surface of the Earth

63

What is the substance needed for burning And breathing

The substance in the air that we need for both burning and breathing is oxygen

64

What is the composition of the air

Nitrogen 78%
oxygen 21%
carbon dioxide 1%

65

What does the word inert mean

The word inert it means unreactive it is very difficult to get these gases to take part in any reaction therefore there called inert gases or noble gases

66

Who was oxygen discovered bye

Joseph priestly and Antonine lovoisier

67

What is one of the simplest methods of preparing oxygen

One of the simplest method of preparing oxygen in the laboratory is by decomposing (breaking down ) hydrogen peroxide

68

What is hydrogen peroxide

Hydrogen peroxide is a colourless liquid that decomposes to give off oxygen and form water

69

What is the word equation for hydrogen peroxide water and oxygen

Hydrogen peroxide -> water + oxygen

70

What is the chemical equation for hydrogen peroxide water and oxygen

2H2O2 -> 2H2O + O2

71

What is magnesium dioxide

Magnesium dioxide is a catalyst MNO2 does not use up in the reaction and does not appear in the chemical equation used to make hydrogen peroxide decompose

72

What is a catalyst

A catalyst is a substance that changes the speed of a chemical reaction but is not used up in the reaction itself

73

What are the physical properties of Oxygen

Odourless tasteless colourless
Slightly more soluble in water
Slightly heavier than air

74

Where are the chemical properties of oxygen

It's supports combustion very well
Reacts with most elements to form oxides
It has no effect on with litmus

75

What is acid rain

Acid rain is rain made up of nitric acid and sulfuric acid with a PH of less then 5.5