Chapter 6

Question 1

What is an element?

Answer 1

A pure substance that cannot be broken down into simpler chemical substance by any physical or chemical means

! the building blocks of all substances and arranged on the periodic table

(things on the periodic table)

Question 2

What is an example of an element?

Answer 2

Silver, as it cannot carry out any chemical or physical reactions where silver will convert into something simpler

Question 3

What is an element symbol?

Answer 3

an abbreviation for a chemical element

Question 4

What is a compound?

Answer 4

A pure substance composed of two or more DIFFERENT elements that are chemically joined

Question 5

What is an example of a compound?

Answer 5

Water ; (not an elements but is made up of two elements in the periodic table)

made with: Hydrogen & oxygen

Question 6

What is a metal element?

Answer 6

Located on left & central parts of the periodic table

solids which display a metallic lustre

(lustrous, malleable, ductile, conducts heat & electricity)

Question 7

What are non-metals?

Answer 7

Found in the upper right portion of the periodic table

Mostly gases and dull powdery solids

Does not conduct heat or electricity

Question 8

What is the only non-metal liquid?

Answer 8

Bromine (element 35)

Question 9

What are metalloids?

Answer 9

Located along the staircase line

Have properties of both metals and non-metals

• important use in digital electronices

-typically increases in conductivity as temperature increases

Question 10

What is a chemical family?

Answer 10

column of elements with similar properties on the periodic table
(belong to same group)

Question 11

What are the 7 Diatomic Molecules?

Answer 11

Hydrogen, Nitrogen, Fluoride, Oxygen, Iodine, Chlorine, Bromine

( Have No Fear Of Ice Cold Beer )

Two same elements bonded together, 7 of these Diotomic elements always exist in pairs of 2. (power to 2)

Question 12

What are alkali metals?

Answer 12

Group 1

Very reactive metals that do not occur freely in nature

Valence Electrons: 1

Properties: Malleable, Ductile, good conductors of heat & electricity, softer than most

Can explode if exposed to water

Question 13

Alkaline Earth Metals

Answer 13

Group 2

Very reactive

Valence Electrons: 2
can easily bond with other elements by losing these electrons

Not found free in nature

Question 14

Transition metals

Answer 14

Group 3 - 12

Valence Electrons: may vary

Properties: Ductile, Malleable, conduct electricity and heat

Question 15

Halogens

Answer 15

Group 17

Valence electrons: 7
bonds easily with alkali metals

“SALT FORMER” - very reactive non-metals & forms salt when reacting w metals

Question 16

Noble Gases

Answer 16

Group 18

Valence Electrons: full shell
(prevents gases from forming compounds)

Very stable due to their max electrons in the outershell

Question 17

Rare earth metals

Answer 17

located at the bottom of a periodic table

Question 18

What is Mendeleev’s periodic law?

Answer 18

“If the elements are arranged according to their atomic mass, a pattern could be seen in which similar properties occur regularly”

Question 19

What are the properties of an element and who was this determined by?

Answer 19

Dmitri Mendeleev (1834-1907)

• Atomic Mass
• Density
• Colour
• Melting point
• Boling point

Question 20

Example of noble gases?

Answer 20

low density of helium used in balloons so it could float

Question 21

Example of akaline earth metals?

Answer 21

Magnesium in fireworks
(akaline earth metals burn with a bright flame)

Question 22

Examples of akali metals?

Answer 22

Potassium in plants and foods (bananas, oranges, e.t.c)

Question 23

Example of halogens?

Answer 23

poisonous things, chlorine.

bromine added to lightbulbs to increase brightness and operating life

Question 24

What theory did Democritus & Leucippus discover?

Answer 24

400 BCE (first theory)

“INDIVISIBLE PARTICLE (ATOM)”

showed that atoms are the smallest unit of measurement

• atoms are of different sizes
• atoms are in constant motion
• seperated by empty spaces (the void)

Question 25

What theory did Aristole discover?

Answer 25

450 BCE (second theory) rejected the idea and believed all matter is made up of four substances - earth - water - air - fire

Question 26

What theory did John Dalton propose?

Answer 26

1807 "Billiard Ball Model" - all matter made up of indivisible particles called *ATOMS* - all atoms of an element are identical, and atoms of a different element are different - atoms can be rearranged but never created or destroyed ( Dalton's model couldn't explain attraction between objects )

Question 27

What theory did J.J Thompson propose?

Answer 27

1897 "Plum pudding model" aka ^chocolate chip muffin model - discovered negative particles are called *ELECTRONS* - theorized the rest of the atom is a positvely charged sphere

Question 28

What device did J.J Thompson use to conduct his experiment?

Answer 28

Cathode ray tube the particles he detected were attracted to the positive end of the circut so it had to be negatively charged

Question 29

What theory did Ernest Rutherford propose?

Answer 29

1909 "Gold foil experiment" * DISCOVERED THE NUCLEUS - predicted the presence of positively charged particle called *PROTONS* -

Question 30

What is a proton?

Answer 30

a positvely charged particle in the atom's nucleus

Question 31

What theory did Niels Bohr propose?

Answer 31

1913 "Planetary model of an atom" (how things orbit eachother in an atom) - electrons orbit the nuclus - electrons in an orbit have potential energy, farther away from nucleus = more energy - electrons can jump between orbits (2, 8,8)

Question 32

What theory did James Chadwick propose?

Answer 32

- Discovered neutrons

Question 33

What is an atomic number?

Answer 33

represents the number of PROTONS in an atom

Question 34

what is an atomic mass?

Answer 34

represents the mass of an atom ( # of protons + # of neutrons )

Question 35

What is the formula in a neutral atom?

Answer 35

of protons = # of electrons

Question 36

What is a isotope?

Answer 36

An atom with the same number of protons but different number of neutrons (must be same element)