#2 Elements and Compounds

Question 1

anion

Answer 1

a “negative” ion
it has gained electrons

Question 2

cations

Answer 2

a “positive” ion
it has lost electrons

Question 3

the four categories on the periodic table

Answer 3

Metals (on the left, and some on the right)
Transition Metals (in the center, group B)
Metalloids (the ladder like shape)
Non-metals

Question 4

the smallest chemical unit of matter

Answer 4

atoms

Question 5

which subatomic particle(s) account for most of the volume of an atom?

Answer 5

electrons

Question 6

which subatomic particle(s) account for most of the mass of an atom?

Answer 6

protons and neutrons

mass number (A)

Question 7

what defines the atomic number of an element?

Answer 7

The atomic number (Z) is determined by how many protons the element has.
Carbon has 6 protons and the atomic number 6 (Z=6)

Question 8

how to label an element in a neat square?

Answer 8

top left A (mass number)
bottom left Z (atomic number)
big letter to the right Atomic/element symbol (Cu for example)

Question 9

what is an isotope?

Answer 9

atoms with the same number of protons but different number of neutrons.
That is, the same atomic number (Z) but different mass numbers (A).

Question 10

where did all elements come from?

Answer 10

everything except hydrogen came from stars

Question 11

What is Group 1A called?

Answer 11

Alkali metals
Li, Na, K, Rb, Cs, Fr
are all shiny solids that react vigorously with air, water, and halogens

Question 12

What is Group 2A called?

Answer 12

Alkaline Earth Metals
Be, Mg, Ca, Sr, Ba, Ra
react with water to form alkaline solutions

Question 13

What is Group 6A called?

Answer 13

Chalcogens
O, S, Se, Te, Po

Question 14

What is Group 7A called?

Answer 14

Halogens
F, Cl, Br, I, At

Question 15

What is Group 8A called?

Answer 15

Noble gases
He, Ne, Ar, Kr, Xe, Rn
They are the least reactive elements on the periodic table.

Question 16

What is special about elements in the same group?

Answer 16

Elements in the same group have similar chemical and physical properties

Question 17

Gasses to memorize:

Answer 17

H2, N2, O2, F2, Cl2

Question 18

Liquids to memorize:

Answer 18

Hg and Br2

Question 19

Diatomic elements to memorize:

Answer 19

H2, N2, F2, O2, I2, Cl2, Br2

Question 20

What are allotropes?

Answer 20

forms of the same element that differ in their physical and chemical properties
For example, P and P4

Question 21

what are period 6 and 7 called on the periodic table?

Answer 21

Period 6: Lanthanides
Period 7: Actinides elements

Question 22

About what percentage of elements are metals?

Answer 22

75%

Question 23

Property of metals?

Answer 23

metals are generally shiny solids that are ductile and good conductors of electricity
(Hg is an exception: liquid at room temperature)

Question 24

Property of non-metals?

Answer 24

Nonmetals are generally dull, brittle solids or gases that do not conduct electricity
(Br is an exception: liquid at room temperature)

Question 25

Property of metalloids?

Answer 25

Have properties like metals and non-metals

Question 26

Which elements form allotropes?

Answer 26

C, O, P, and S

Question 27

Which elements are the metals?

Answer 27

Group 1A Group 2A Al Ga In, Sn Tl, Pb, Bi, Po

Question 28

Which elements are the transition metals?

Answer 28

All group B

Question 29

Which elements are the metalloids?

Answer 29

B Si Ge As Sb Te At

Question 30

Which elements are non-metals?

Answer 30

He C N O F Ne P S Cl Ar Se Br Kr I Xe Rn

Question 31

physical and chemical properties of covalent compounds vs ionic compounds

Answer 31

most covalent compounds are gases, liquids, or solids with low melting points, whereas most ionic compounds are solids with very high melting points.

Question 32

what kind of ion does metals usually form?

Answer 32

cations

Question 33

what kind of ion does non-metals usually form?

Answer 33

anions

Question 34

most polyatomic ions are cations or anions?

Answer 34

anions the only cation is ammonium ion (NH4)+