EST final exam Flashcards
(63 cards)
1
Q
what is a covalent bond?
A
a bond resulting from a sharing of electrons
2
Q
what is an ionic bond?
A
a bond resulting from the gain or loss of electrons
3
Q
2
What is the atomic number?
A
- Its at the top of the symbol of the element.
- It is the number of protons in that element.
4
Q
Where and what are neutrons?
A
- neutral particles
- found inside the nucleus
5
Q
how do you draw the simplified atomic model
A
- calculate the number of protons, neutrons, electrons
- draw the nucleus and place isnide the protons and neutrons (p+= , no= )
- draw shells around the nucleus in corespondance with the amount of electrons
6
Q
What is 2, 8, 8, 2 mean?
A
Amount of electrons that should be found on the orbitals/shells
7
Q
how to find the mass number
A
round the atomic mass (found below the symbol)
8
Q
How do you find the subatomic particle: neutrons?
A
Mass number - #protons = #neutrons
9
Q
What is the formula for Ammonium?
A
NH₄ (+)
10
Q
What is the formula for Hydroxide?
A
OH(-)
11
Q
What is the formula for Nitrate?
A
NO₃(-)
12
Q
What is the formula for Sulfate?
A
SO₄(2-)
13
Q
What is the formula for Carbonate?
A
CO₃(2-)
14
Q
What is the formula for Phosphate?
A
PO₄(3-)
15
Q
NH₄ (+)
A
Ammonium
16
Q
OH(-)
A
Hydroxide
17
Q
NO₃(-)
A
Nitrate
18
Q
SO₄(2-)
A
Sulfate
19
Q
CO₃(2-)
A
Carbonate
20
Q
PO₄(3-)
A
Phosphate
21
Q
List all the names of the polyatomics ions to memorise:
A
1.Ammonium
2.Hydroxide
3.Nitrate
4.Sulfate
5.Carbonate
6.Phosphate
22
Q
How do you name compounds containing polyatomic ions?
A
1.Name the cation first (positive ion/polyatomic ion)
2.Name the anion (negative ion/polyatomic ion)
3.DO NOT change the ending to “ide”
23
Q
How do you name a simple ionic compound?
A
- Name the metal first (capitalized)
- Name the non-metal second and change the ending to “ide”
24
Q
How do you determine the subscripts in a simple ionic compound?
A
with the crossover rule
1.Determine the ion formed by the metal and the non-metal
2.Write the elements sided by side with the metal first.
3.Cross-over the charges so that the charge of the metal becomes the subscript of the non-metal and vise-versa.
4.Simplify if possible. (there are no signs)
25
How do you write the formula for ionic compounds containing polyatomic ions?
1. The CROSS-OVER rule applies because they are ionic bonds
2. Treat the polyatomic ion as if it were a single atom
3. cant touch this
MAKE SURE TO PUT BRACKETS
26
How do you name ionic compounds containing transition metals ?
1. To determine the charges we will uncross the subscripts.
2. Next check to see if the charge of the known element (the non-metal) is correct.
3. If it is then the charge of the transition metal is also correct.
4. If it is not correct, un-simplify the charges by multiplying both charges by the necessary value. Now the charge of the transition metal will be correct.
5. Place the charge of the transition metal in brackets after its name. (ROMAN)
27
How do you write the formula for ionic compounds containing transition metals ?
1. Use the cross over rule as you would a regular ionic bond.
2. Use the charge given in brackets for the nontransitional-metal and look for the charge of the anion on the periodic table.
28
List the roman numerals
l, ll, lll, lV, V
29
How do you name the formula for covalent bonds?
1. Name the least electronegative non-metal first with the appropriate prefix. (Exception: Do not use mono prefix for first non-metal)
2. Name the second non-metal with the appropriate prefix and change the ending to “ide”.
30
List all the prefixes:
1 mono
2 di
3 tri
4 tetra
5 penta
6 hexa
7hepta
8octa
9nona
10deca
31
How do you write the formula for covalent bonds?
1. Write the symbols for each element.
2. The subscript is determined by the prefix.
3. Do not simplify.
32
what is a mole?
- the unit of measure of the amount of a substance
- avogadro's number: 6.02 x 10 to the power of 23 atoms/molecules
33
what is an isotope?
atoms of the same element whose nuclei have different numbers of neutrons so their atmoc masses are different
34
what is a radioactive isotope?
an isotope whose atomic nucleus is unstable
35
Period vs group?
Periods (horizontal row) indicates the number of shells/orbitals in an atom.
Groups ( vertical column) indicates the number of valence electrons. (electrons that exist on the outermost shell)
36
Atomic number increases by a constant rate across a BLANK. Atomic mass increases across a period, but not at a BLANK.
period, constant rate
37
The atomic radius BLANK across a period
The atomic radius BLANK down a family
decreases, increases
38
The ionization energy BLANK across a period.
The ionization energy BLANK down a family.
increases, decreases
39
The electronegativity BLANK across a period.
The electronegativity BLANK down a family.
increases, decreases
40
What is ionization energy?
The amount of energy needed to completely remove and electron from a neutral atom.
41
What is electronegativity?
The force of attraction between an atom's nucleus and its e-.
42
What peaks in the middle of the Periodic table?
Density, melting point and boiling point.
Increases moving left to right across the metals.
43
Reactivity BLANK across a period
Reactivity BLANK down a group/family
decreases, increases
44
What is the difference between an exothermic reaction and an endothermic reaction?
An exothermic reaction is when heat\energy is released, while an endothermic reaction is when heat/energy is absorbed.
45
How to determine in a chemical euqation is its an endo or exothermic reaction?
So exothermic, the energy is on the product side, while endothermic, the energy is on the reactant side.
46
what is buffering cappacity of a soil
it's ability to limit pH variations
47
what are the avantages of a good soil buffering capacity
48
how do you read a resistor?
1. the 1st and 2nd band give you the first 2 digits
2. the 3rd band is the **exponent** on ten by which the 2 first digits are multiplied by
3. the 4th band is the tolerance of the resistor (+or-%) (5% = 0.05)
IT WILL BE IN A RANGE ( [5Ω, 10Ω])
49
explain the process of eutrophication
1. algae feed on nitrogen and phosphorus from fertilizer run-off. This explosion of growth is called an algal bloom.
2. As the algae dies, it sinks to the bottom, where it is decomposed by microorganisms. (decomposers)
3. The microgoraganisms comsume lots of oxygen as they decompose the organic matter. Therefore, the amount dissolved O2 in the water significantly decreases.
4. Other aquatic organisms (fish,frogs,insects) do not have enough oxygen for respiration
5. Slowly, the ecosystem dies
50
how does eutrophication occur? ad how do humans accelerate it?
- when an excess of organic material and nutrients (rich in nitrogen and phosphorus) accumulate in waterways (rivers)
- run off of fertilizer, pesticides, septic leaks and detergents contain phosphates an nitrogen rich molecules
51
what is the purpose of limiting motion (degree of freedom) in a technical object give exemple
to create stability, control, and prevent unwanted movement
exemple: some hinges limit how far a cupboard door can open or prevent it from hitting the wall
52
describe how to use the **right** hand rule
- conventional current goes + to - so point your thumb towars - (aka away from positive)
- then your fingers wrap in the direction of the magnetic field
53
describe how the OTHER right hand rule works for solenoids?
- first wiht your right hand wrap your finger in the direction of the conventional current (aka the way the wires coil)
- then your thumb is pointing to the direction of the NORTH pole of the magnet
54
how can the power of an electromagnet be increased
1. using a ferromangetic core with a lower magnetic remenance
2. increasing the current intensity
3. adding more loops
55
what is effective force
the component of the applied force parallel to the direction of travel
56
what is a contaminant
an agent that causes changes in the physical,chemical or biological properties of an environment or an organism
57
what is bioaccumulation
the process by which a contaminant from the environment or food supply accumulates in an organism
58
# from...
what is bioconcentration
a special case of bioaccumulation by which an organism accumulates a contaminant through direct contact with its environment (from sources other than food)
59
# (?)
what is the toxicity treshold of a substance?
the minimum concentration of a substance that produces a significant harmful effect in an organism (mg/kg of the organism's mass)
60
what is an allele
a possible form of a gene
61
what is a homozygote
an individual with two identical alleles for a particular character trait
62
what is a heterozygote
an individual with two different alleles for a particular character trait
63
