ch3

Question 1

Electron relative mass

Answer 1

1/1836

Question 2

What is proton number?

What are the other terms used interchangeably with it?

Answer 2

The number of protons in an element/compound

other terms
atomic number

Atomic number: Number of protons in an element/compound

Atomic Mass (Ar): Number of protons/electrons in an element

Molecular Mass (Mr): Number of protons/electrons in a compound/mixture

p.s. no such thing as molecular number

Question 3

Nucleon number

Terms used interchangeably with it

Answer 3

Total number of protons and neutrons in an atom

Ar/Atomic Mass/Relative Molecular Mass

Question 4

Octet configuration

Answer 4

8 valence electrons

alt. answer
8 electrons in valence shell

Question 5

Duplet configuration

Answer 5

2 electrons in valence shell

Question 6

A compound with the following ends:

-ate (e.g. nitrate)
-ide (e.g. nitride)

Which one has oxygen in chem. formula, which one dosen’t

Answer 6

ate - oxygen
ide - no oxygen

Question 7

Match following keywords w/ number
tetra
mono

Answer 7

4
1

Question 8

Chemical bond strength of force

Answer 8

very strong

Question 9

Silver charge
Zinc charge

Answer 9

Silver
Ag +

Zinc
Zn 2+

Question 10

Is the metal written in the front or the back in a chemical formulae

Answer 10

Front

E.g. NaCl (Na aka Sodium is from grp 1 so it is a metal)

No one puts ClNa, they put NaCl as Na is the metal

Question 11

Define Mr Value

Answer 11

average mass
(isotopes of element)
compared
1/12th mass (1 atom C-12)

Question 12

Which grp an atom belongs to?
+ Which grp is noble gas?

Answer 12

Metallic (<= 3 Valence)
G1, 2, 3

Non-metallic (>3 valence)
G (10 + Valence e-)

Noble gas
G18

Question 13

Why is noble gas stable

Answer 13

full valence shell, cannot react with other atoms

Octet config not accepted. Helium is a duplet config yet it is stable

Valence electrons = outermost electrons

Question 14

charge of bromine

Answer 14

Br-

Question 15

is bromine a metal
is barium a metal
is sulfur a metal

Answer 15

bromine: nonmetal
barium: metal
sulfur: nonmetal

check periodic table!!

Question 16

define elements

Answer 16

pure substance, cannot broken down any simpler substances by chemical methods

Question 17

when do molecules of elements form? are they still elements?

Answer 17

molecules of elements -> 2 or more atoms, same elements, chemically bonded together

yes, they are still elements

Question 18

2 general classification of elements

Answer 18

metal
non metal

Question 19

define compounds

Answer 19

pure substances, atoms of two/more different elements, chemically bonded

Question 20

properties of compound

Answer 20

• properties different from constituent elements
• made of fixed ratio of atoms
• constituent elements only separated via chemical methods

Question 21

how to form mixture?

Answer 21

2 diff. elements not chemically bonded tgt

2 diff. compounds not chemically bonded tgt

elements + compounds not chemically bonded tgt

NOT formed by chemical reactions

Question 22

define mixture

Answer 22

different substances exsisting tgt,
not chemically bonded tgt

Question 23

how does impurities affect melting pt?

Answer 23

• melt over range of temp.
• below pure substance melting pt.

i.e.

pure substance X 90 deg melting, 100 deg boiling becomes a wider scope.

impure substance X 70-89deg melting, 101-150deg boiling

Question 24

how does impurities affect boiling pt?

Answer 24

• boils over range of temp.
• above pure substance boiling pt.

i.e.

pure substance X 90 deg melting, 100 deg boiling becomes a wider scope.

impure substance X 70-89deg melting, 101-150deg boiling