The Atom + Arrangements of Electrons in the Atom

Question 1

Chemistry

Answer 1

Branch of science that deals with the structure and composition of matter and the reactions needed to change it from 1 substance to another

Question 2

Matter

Answer 2

Anything that occupies space and has mass

Question 3

Mixture

Answer 3

2 or more substances MINGLED together but not chemically combined

Question 4

an Element

Answer 4

a substance that cannot be split into simpler substances by chemical means

Question 5

Compound

Answer 5

2 or more elements chemically combined

Question 6

Atoms

Answer 6

smallest particle of an element that can exist on its own

Question 7

Molecule

Answer 7

2 or more atoms chemically combined together

Question 8

Ions

Answer 8

charged atoms

Question 9

Cations

Answer 9

positively charged ions due to loss of electrons from an atom

Question 10

Anions

Answer 10

negetively charged ions due to gain of electrons by an atom

Question 11

Prove the particular state of matter

Answer 11

(diagram of ammonia and hydrochloric acid meet to create a ring of ammonium chloride)

Question 12

Law of Conservation of Matter/Energy/Mass

Answer 12

Matter is neither created nor destroyed during a chemical reaction, it simply changes from 1 form into another

Question 13

Discharge Tube

Answer 13

• A long glass tube with a metal electrode at each end of the tube
• and the gas inside at very low pressure (almost vaccum)
• passing electricity through tube produced invisible rays,
• moving from the cathode to the anode
• > cathode rays causing glass to fluoresce

Question 14

Diffusion

Answer 14

spontaneous spreading out of a substance due to the natural movement of its particles

Question 15

Brownian motion

Answer 15

Random, rapid movement of particles

Question 16

Name 3 sub-atomic particles (subs.)

Answer 16

Protons
Neutrons
Electrons

Question 17

Prove cathode rays travel in straight lines

Answer 17

(William Crooke’s diagram of maltese cross casting shadow in discharge tube)

Question 18

Prove cathode rays posess energy

Answer 18

(William Crooke’s diagram of paddle wheel apparatus)

Question 19

Dalton’s Atomic Theory

Answer 19

• very small particles called atoms
• atoms are indivisable and indestructable
• all atoms identical to each other in mass and chemical properties
• compounds ->2 or more elements combined together in fixed proportions

Question 20

Ancient Greek Philosophers proposed that…

Answer 20

-matter composed by ‘indivisable particles’

Question 21

JJ Thompson found…

Answer 21

-cathode rays attracted to positive charged plate = negetively charged particles
-RATIO of ELECTRON CHARGE to ELECTRON MASS
e/m ratio
-plum pudding model

Question 22

Electromagnet

Answer 22

a magnet that’s formed by passing a current through a wire wrapped tightly round a piece of metal

Question 23

Deflection

Answer 23

moved from its original path

Question 24

In 1891, Johnston Stoney…

Answer 24

named the electron

Question 25

Robert Milikan...

Answer 25

conducted OIL DROP experiment measuring exact charge on electrons -> substituted the charge into e/m ratio and calculated exact mass of electron

Question 26

Rutherford Alpha Particle Scattering Experiment

Answer 26

(diagram of alpha particles fired at gold sheet )

Question 27

[Rutherford Alpha Particle Scattering Experiment] a VERY LARGE NUMBER of alpha particles... Therefore...

Answer 27

𝗥𝗘𝗦𝗨𝗟𝗧: passed straight through gold foil -> UNDEFLECTED | 𝗖𝗢𝗡𝗖𝗟𝗨𝗦𝗜𝗢𝗡 𝗮𝗯𝗼𝘂𝘁 𝗔𝗧𝗢𝗠𝗜𝗖 𝗜𝗖 𝗦𝗧𝗥𝗨𝗖𝗧𝗨𝗥𝗘: Atoms are mostly EMPTY SPACE

Question 28

[Rutherford Alpha Particle Scattering Experiment] MANY alpha particles... Therefore...

Answer 28

𝗥𝗘𝗦𝗨𝗟𝗧: deflected at small angles and a small number were deflected at larger angles 𝗖𝗢𝗡𝗖𝗟𝗨𝗦𝗜𝗢𝗡 𝗮𝗯𝗼𝘂𝘁 𝗔𝗧𝗢𝗠𝗜𝗖 𝗜𝗖 𝗦𝗧𝗥𝗨𝗖𝗧𝗨𝗥𝗘: Repulsion of particles coming close to small dense concentration of positive charge = NUCLEUS

Question 29

[Rutherford Alpha Particle Scattering Experiment] | a VERY SMALL NUMBER of alpha particles...

Answer 29

𝗥𝗘𝗦𝗨𝗟𝗧: bounced back along their own path | 𝗖𝗢𝗡𝗖𝗟𝗨𝗦𝗜𝗢𝗡 𝗮𝗯𝗼𝘂𝘁 𝗔𝗧𝗢𝗠𝗜𝗖 𝗜𝗖 𝗦𝗧𝗥𝗨𝗖𝗧𝗨𝗥𝗘: alpha particles colliding head on with NUCLEUS

Question 30

orbit

Answer 30

energy level fixed path that an electron occupies

Question 31

Rutherford also...

Answer 31

- Rutherford's Model of the atom- NUCLEUS + electrons outside - > Knocked out positively charged particles = PROTONS - predicted nucleus had other particles wth same mass but NO charge

Question 32

James Chadwick found...

Answer 32

NEUTRONS and neutrons having same mass as protons

Question 33

Niels Bohr found...

Answer 33

Orbits and energy levels for electrons

Question 34

A.M.U.

Answer 34

Atomic Mass Unit

Question 35

Atomic Number (Z) of an element

Answer 35

no. of protons in the nucleus of an atom of an element

Question 36

Mass Number (A) of an atom

Answer 36

the sum of the protons and neutrons in the nucleus

Question 37

Nuclear format of an element

Answer 37

Periodic table elements turned upside down

Question 38

Isotopes

Answer 38

atoms of the same element with the same Atomic number but different MASS numbers due to different number of neutrons in nucleus of each atom

Question 39

Reletive Atomic Mass (Aᵣ) of an element

Answer 39

The average mass of an atom of an element reletive to ¹⁄₁₂ the mass of a Carbon-12 atom

Question 40

Principle of the Mass Spectrometer

Answer 40

positively charged ions are deflected to different extents and seperated on the basis of their reletive masses in a magnetic field

Question 41

[Mass Spectrometer] | Vapourisation

Answer 41

inlet that contains a heater to vapourise non-gasous samples

Question 42

[Mass Spectrometer] | Ionisation

Answer 42

electron gun fires electrons at sample atoms, knocking electrons out of sample atoms forming positively charged ions

Question 43

[Mass Spectrometer] | Acceleration

Answer 43

electric field(negetively charged plates) concentrates ions into narrow beam and causes them to move at high speeds

Question 44

[Mass Spectrometer] | Seperation

Answer 44

magnetic field seperates ions based on their masses

Question 45

[Mass Spectrometer] | Detection

Answer 45

ions strike a detection screen and the abuncance of each is recorded

Question 46

Uses of the Mass Spectrometer:

Answer 46

- To calculate Aᵣ of an element | - to calculate the masses and abundance of isotopes

Question 47

3 states of matter:

Answer 47

Solids Liquids Gases