Chem unit

Question 1

Bohr diagrams & important info you need to know about them

Answer 1

n = mass #- atomic

-aka energy level diagrams
protons and neutrons are found in the nucleus
-electrons are found in the energy levels
1st energy shell =max of 2e-
2nd energy shell= max of 8e-
3rd energy shell =max of 8e-

atomic number= number of p+ or the number of e-

Question 2

valence level

Answer 2

the outer most energy level
-electrons in this level are called valence electrons
to become stable,atoms gain,lose or share electrons so that their valence level has the maximum number of electrons and they will have the valence electron configuration of a noble gas

Question 3

a chemical bond

Answer 3

the force of attraction between atoms

two types are covalent and ionic

Question 4

a covalent bond

Answer 4

aka molecular bonds
-forms when two atoms share valence electrons
-occurs between two or more nonmetals
- solutions of covalently bonded substances are non-electrolytic ( they d not conduct)
-

Question 5

ionic bond

Answer 5

a force of attraction between a cation(positive) and an anion ( negative). usually between a metal and a nonmetal
-solutions of ionic compounds = electrolytic

Question 6

electrolytes
and
nonelectrolyes

Answer 6

electrolytes- a solution that conducts electricity ( general examples ionic compound,acids- specific fruit juice , salt in water ,vinegar,lemon juice etc)

non-electrolytes -a solution that does not conduct electricity (general examples include molecular compounds- Specific examples =sugar in water,ASA, Vitamin C

Question 7

IUPAC

Answer 7

international Union of Pure and Applied Chemists
a global organization that sets standards in chemistry
one job of Iupac is to give compounds systematic names

Question 8

PS HOFBrINCl

Answer 8

the diatomic elements

(except is is P4 and S8

Question 9

what are the prefixes for naming molecular compounds

Answer 9

1-mono or mon
2- di
3-tri
4-tetra
5-penta
6-hexa
7-hepta
8-octa
9-nona
10-deca

Question 10

what are some trivial name molecular compounds

Answer 10

aka common molecular compounds ( they have common names

examples

03-Ozone
H20-water
H202-hydrogen peroxide
NH3-ammonia
CH4-methane
CH3OH-methanol
C2H5OH-ethanol
C6H12O6-glucose
C12H22O11-sucrose( sugar?)

Question 11

ions

Answer 11

atoms other than the noble gases are unstable and need to gain ,lose of share to become more stable
-sharing electrons results in a covalent bonds ( molecular compounds)
-if they lose or gain electrons ,become ions and form ionic bonds with other atoms
thus, an ion are charged particles that have lost of gained electrons to achieve the valence configurations of a noble gas

Question 12

what is the octet rule

Answer 12

that atoms that have an octet of valence electrons are stable and unreactive
-its is duet fro hydrogen and lithium

Question 13

cations

Answer 13

• positive ions that form when an atom loses an electrons
• a cation has more protons than electrons ,therefore it has an overall positive charge
• metals form cations

Question 14

anions

Answer 14

negative ions that have formed when an atom gains electrons
it has more electrons than protons and therefore has a negative charge
nonmetals form anions

Question 15

ionic compounds

Answer 15

composed of a cation(metal) and an anion(nonmetal)
-ionic bond is the force of attraction between these oppositely charged e-
ions stay together in crystal lattice

Question 16

multivalent ionic compounds

Answer 16

ions of some transition elements can have more than one possible charge
-such elements are called multivalent
we use roman numerals to indicate the charge on these ions

Question 17

polyatomic ions

Answer 17

-are a group of atoms acting as one ion,carrying an overall charge

Question 18

hydrated ionic compounds

Answer 18

• hydrated ionic compounds have water attached to their crystal lattice structure
• solutions become hydrated when they are crystallized from a water solution
• they are often recognizable by eye b/c they are shinny and translucent

not anhydrous ,means no water attached

Question 19

acids

Answer 19

form when hydrogen compounds dissolve in water

• the subscript (aq) indicates aqueous which means dissolved in water
• acid molecules ionize in water to produce hydrogen ions (H+)

Question 20

properties of acids and bases

Answer 20

ACIDS

• tastesour
• reacts with metals and carbonates
• Ph is less than 7
• conducts electricity

BASES

• bases are bitter
• feels slippery
• Ph is greater than 7
• conducts electricity

Question 21

what are the endings for naming acids

Answer 21

• hydrogen___ide —–> hydro___ic acid
  -hydrogen___ate ——-> _____ic acid
  hydrogen____ite—–> ____ous acid

Question 22

what are the six types of chemical reactions

Answer 22

1. simple composition
   -element +element=comppound
   2.simple decomposition
   -compound=element+element
   3.single replacement
   -element+compound=compound+element
   4.double composition
   compound+compound=compound+compound
   5.Hydrocarbon combustion
   CxHy+O2=CO2+H2O
2. neutralization
   acid+base =salt +H2O

Question 23

What are the colour of ionic and molecular solutions?

Answer 23

Ionic - can be colourless and coloured

Molecular- can only be colourless