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Question 1

Define the word element

Answer 1

An element is a substance that is made up of only one kind of atom.

Question 2

how to familiar substances. as elements or.compound

Answer 2

A substance that cannot be broken down into chemically simpler components is an element.

Question 3

describe familiar chemical reactions in word equations.

Answer 3

potassium hydroxide + sulfuric acid → potassium sulfate + water.

Question 4

state that mass is conserved in a
chemical reaction.

Answer 4

no atoms. are lost or made in a chemical reaction.

Question 5

describe the basic structure of an
atom.

Answer 5

an extremely small, positively charged nucleus surrounded by a cloud of negatively charged electrons

Question 6

what are compounds

Answer 6

compounds contain two or more diffrent elements chemically combined in fix proportions.

Question 7

what are mixture

Answer 7

we have a diffrent elements or compound but they’re not chemically combined

Question 8

explain the significance of chemical
symbols used in formulae and equations.

Answer 8

Symbols help simplify the process of identifying and explaining chemical formulas.

Question 9

explain why mass is conserved in a
chemical reaction.

Answer 9

No new atoms have entered or left the system

Question 10

explain why mass is conserved in a
chemical reaction.

Answer 10

No new atoms have entered or left the system

Question 11

justify in detail how mass may appear
to change in a chemical reaction.

Answer 11

If a gas escapes, the total mass will look as if it has decreased

Question 12

describe familiar chemical reactions
with balanced symbol equations
including state symbols.

Answer 12

Thermal Decomposition of Calcium Carbonate. Reaction: Calcium carbonate decomposes when heated.
Equation:
CaCO3(S) CaO(s)+CO2(g)

Question 13

describe unfamiliar chemical reactions
with more complex balanced symbol
equations, including state symbols.

Answer 13

synthesis of ammonia
N2(g)+3H2(g)-)2NH3(g)

Question 14

balance given symbol equations.

Answer 14

Unbalanced Equation
Fe+O2-)Fe2O3
balanced equation
4Fe+3O2-)2Fe2O3

Question 15

balanced symbol equations.

Answer 15

A balanced symbol equation represents a chemical reaction where the number of atoms for each element is the same on both sides of the equation.

Question 16

balanced symbol equations.

Answer 16

A balanced symbol equation represents a chemical reaction where the number of atoms for each element is the same on both sides of the equation.

Question 17

difference between compound and mixture

Answer 17

Compound:

Elements bonded together.
Fixed composition.
Mixture:

Substances combined, not bonded.
Variable composition.

Question 18

explain how the chemical
properties of a mixture relate to the
chemical it is made from.

Answer 18

Each substance in a mixture retains its own properties.
The overall properties depend on the substances present.

Question 19

suggest an appropriate separation or
purification technique for an unfamiliar
mixture.

Answer 19

You have a mixture of colored substances (like inks or dyes) or different soluble compounds.

How It Works:

The mixture is placed on a stationary phase (like paper).
A solvent moves through the mixture, separating the components based on their different affinities for the stationary phase and the solvent.

Question 20

list different separation techniques.

Answer 20

Filtration
Separates solids from liquids.

Distillation
Separates liquids based on boiling points.

Evaporation
Removes a solvent to leave solid residues.

Question 21

explain in detail how multi-step
separation techniques work.

Answer 21

Filtration: Separates solids from liquids using a filter.

Evaporation: Removes the liquid to leave solid residues.

Distillation: Separates liquids by heating; collects vapor of the lower boiling liquid.

Chromatography: Uses a solvent to
separate components based on movement.

Question 22

state when fractional distillation would
be used.

Answer 22

For example, fractional distillation is used in oil refineries to separate crude oil into useful substances

Question 23

list the significant models proposed
for atoms.

Answer 23

Early atomic models.
Dalton’s atomic model.
The Thomson atomic model.
The Rutherford atomic model.
The Bohr atomic model.
Quantum atomic model.
Modern atomic model.

Question 24

describe the process of fractional
distillation.

Answer 24

a mixture of liquids is boiled and the resulting vapors travel up a glass tube called a “fractionating column” and separate

Question 25

explain the main processes occurring in paper chromatography.

Answer 25

. The solvent travels up the paper, carrying the ink with it, and the ink separates out into all of its different coloured components.

Question 26

explain in detail how fractional distillation can separate miscible liquids with similar boiling points.

Answer 26

the vapour condense when they reach a part of the column that is below the temperature of their boiling point.

Question 27

purification techniques for a given mixture.

Answer 27

Filtration is a solid-liquid purification technique used to separate solids from a liquid, in a suspension.

Question 28

identify the key parts of the plum- pudding model and the nuclear model of the atom.

Answer 28

the electrons were embedded in a uniform sphere of positive charge,nuclear model the mass of an atom is concentrated at its centre, the nucleus. It contains protons and neutrons, and has most of the mass of the atom. The plural of nucleus is nuclei. the nucleus is positively charged.

Question 29

why the model of the atom has changed over time.

Answer 29

The atomic model has changed over time due to advancements in technology and scientific understanding

Question 30

describe the differences between the plum-pudding and the nuclear model of the atom.

Answer 30

This model did not propose the existence of a concentrated nucleus; instead, it suggested a uniform distribution of charge throughout the atom. Nuclear Model: The nucleus was introduced as a central, positively charged region containing most of the atom's mass and positive charge.

Question 31

explain how evidence from scattering experiments changed the model of the atom.

Answer 31

The fact that most alpha particles passed straight through unscattered suggested that the atom is mostly empty space.

Question 32

evaluate the current model of an atom.

Answer 32

quantum mechanical model and has inside nuclues that contains and neutral and positive charge and a outer shell of negative charge electrons

Question 33

state the relative charges and masses of subatomic particles.

Answer 33

If a proton has a charge of +1, then an electron has a charge of -1.

Question 34

describe atoms using the atomic model.

Answer 34

The atomic model consists of a nucleus containing protons and neutrons, surrounded by electrons in shells.

Question 35

state that atoms have no overall charge

Answer 35

they contain equal numbers of positive protons and negative electrons.

Question 36

explain why atoms have no overall charge.

Answer 36

they contain equal numbers of positive protons and negative electrons.

Question 37

label the subatomic particles on a diagram of a helium atom.

Answer 37

2 electrons and 2 protons.

Question 38

explain why we can be confident that there are no missing elements in the first 10 elements of the periodic table.

Answer 38

Since protons cannot be split

Question 39

state what an ion is.

Answer 39

An ion is an atom or group of atoms that has an electric charge.

Question 40

describe isotopes using the atomic model.

Answer 40

Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons

Question 41

define an isotope.

Answer 41

Isotopes are forms of an element that have the same number of protons but different numbers of neutrons.

Question 42

explain why ions have a charge.

Answer 42

Gaining electrons or losing electrons creates an ion.

Question 43

state the relative sizes of an atom and its nucleus.

Answer 43

The diameter of an atom is on the order of 10−10 m, whereas the diameter of the nucleus is roughly 10−15 m—about 100,000 times smaller.

Question 44

atomic number and mass numbers of familiar ions to determine the number of each subatomic particle.

Answer 44

number of protons = atomic number.

Question 45

explain why chlorine does not have a whole mass number.

Answer 45

Because of something called isotopes, chlorine has an atomic weight of 35.5 instead of 35.

Question 46

state that electrons are found in energy levels of an atom.

Answer 46

the electrons orbit the nucleus of the atom.

Question 47

standard electronic configuration notation from a diagram for the first 20 elements.

Answer 47

How many electrons are on each shell such as Nitrogen 2,5

Question 48

state the maximum number of electrons in the first three energy levels.

Answer 48

The maximum number of electrons in the first energy level is 2.

Question 49

explain why elements in the same group react in a similar way .

Answer 49

The elements in the same group have the same number of electrons in their outermost shell, also known as valence electrons.

Question 50

make predictions for how an element will react when given information on another element in the same group.

Answer 50

Such as noble gases are so reactive the more it goes down the group it gets even more resctive

Question 51

What is an element

Answer 51

substance that is made up of only one kind of atom.

Question 52

Why in rutherfords experiment they deflected

Answer 52

Because of the positvie and electron not having the same charge which cause them to repel and very few deflected/bounced back

Question 53

describe the basic structure of an atom.

Answer 53

Protons and neutrons in the center and a outer shell of electrons

Question 54

classify familiar substances as elements or compounds.

Answer 54

Water (H2O), Sodium chloride (NaCl), Sodium bicarbonate (NaHCO3) and Hydrochloric acid (HCl) are examples of compounds

Question 55

explain in detail, including diagrams, the difference between a pure element, mixture and compound.

Answer 55

An element is a pure substance which contains identical atoms or molecules with only one type of atomic core. A compound is a pure substance which contains identical molecules with two or more types of atomic core. A mixture is a material which has two or more types of molecules.

Question 56

explain the significance of chemical symbols used in formulae and equations.

Answer 56

Symbols help simplify the process of identifying and explaining chemical formulas.

Question 57

explain why mass is conserved in a chemical reaction.

Answer 57

No new atoms have entered or left the system

Question 58

justify in detail how mass may appear to change in a chemical reaction.

Answer 58

If a gas escapes, the total mass will look as if it has decreased.

Question 59

state that mass is conserved in a chemical reaction.

Answer 59

the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction.

Question 60

Berlyuim 6 marker

Answer 60

2 outer electrons that means its in group 2, because it has 4 total electrons there must be another shell of 2 shells telling us its in period 2. And to the protons of it is 4 is four and also electrons 4 and protons 4 because you do atomic number-mass number. For position protons and neutrons are in the nuclues of an atom and electrons are in the shells surrounding the nuclues