2| Atoms, Molecules, Ions

Question 1

Dalton atomic theory postulate 1

Answer 1

Each element is composed of extremely small particles called atoms.

Question 2

Daltons atomic theory postulate 2

Answer 2

All atoms of a given element are identical but the atoms of one element are different from the atoms of all other elements.

Question 3

Daltons atomic theory postulate 3

Answer 3

Atoms of 1 element cannot be changed into atoms of a different element by chemical rxns, atoms are neither changed nor destroyed.

Question 4

Daltons atomic theory postulate 4

Answer 4

Compounds are formed when atoms of more than 1 element combine, a given compound always has the same relative no. and kind of atoms.

Question 5

Laws that Daltons theory explains

Answer 5

Law of Constant Composition based on postulate 4
Law of Conservation of mass based on postulate 3

Question 6

Law of Constant Composition

Answer 6

In a given compound, the relative numbers and kinds of atoms are constant

Question 7

Law of Conservation of Mass

Answer 7

The total mass of materials present after a chemical rxn is the same as total mass after rxn

Question 8

Daltons theory is used to deduce

Answer 8

Law of Multiple Proportions

Question 9

Law of Multiple Proportions

Answer 9

If 2 elements A & B combine to form +1 compounds, the masses of B that can combine with given mass of A are in the ratio of small whole numbers.

Question 10

Scanning Tunneling Microscopy

Answer 10

Technique used to provide pictures of atoms.

Question 11

Subatomic particles

Answer 11

Particles such as protons, neutrons, electrons that are smaller than an atom

Question 12

Cathode rays

Answer 12

Streams of electrons that are produced when high voltage is applied to the electrodes in an evacuated tube

Question 13

Atomic no.

Answer 13

Number of protons in the nucleas of an atom

Question 14

Basix forces in nature

Answer 14

Gravitational
Electromagnetic
Strong nuclear
Weak nuclear

Question 15

Gravitational forces

Answer 15

Attractive forces that act between all objects in proportion to their masses. Since atoms have less mass gravity is chemically insignificant

Question 16

Electromagnetic forces

Answer 16

Attractive or repulsive forces acting between electrically charged or magnetic objects

Question 17

Strong nuclear force

Answer 17

Not in hydrogen as it only has 2 or more protons cause repulsion.
When particles are extremely close.

Question 18

Weak nuclear force

Question 19

Thomsons experiment

Answer 19

Behavior of cathode rays in magnetic and electric field.
Discovered the electron and measured charge to mass ratio

Question 20

Milikans oil drop experiment

Answer 20

Determined charge of electron

Question 21

Becquerels discovery of radioactivity

Answer 21

Spontaneous emission of radiation by atoms gave further evidence that the atom has a substructure

Question 22

Rutherfords study

Answer 22

How particles scatter when passing through thin metal foils.
Lead to nuclear model of atoms show how dense atom is, positively charged nucleas.

Question 23

Magnitude of charge

Answer 23

1.602×10^-19 C

Question 24

1amu

Answer 24

1.66054×10^-24g

Question 25

Angstroms

Answer 25

A (dimension of atoms) = 10^-10m

Question 26

Isotope

Answer 26

Atoms of the same element yet different mass number.

Question 27

Ionic compound

Answer 27

Electrically neutral compounds as they contain both metallic and non metallic elements

Question 28

Chemical nomenclature

Answer 28

Set of rules for naming chemical compounds