Download Test Review: Unit 1 - Ms. Hill`s Pre

Test Review: Unit 1
1. Hypothesis: Written in third person and with an “If, Then” Format.
a. Example: If given the density and aluminum and measure mass, length,
and width of aluminum foil, then the thickness (h) can be calculated. Pg
30
2. Independent and dependent variables
3. Atom: Smallest unit of an element that maintain the chemical identity of that
element. Pg6
4. Element: a pure substance that cannot be broken down into simpler, stable
substances and is made of one kind of atom. pg 6
5. Compound: Is a substance that CAN be broken down into simpler stable
substances because it is made of two or more different elements. Pg 6
6. Know the elements corresponding to the atomic numbers 1-36, Hydrogen through
Krypton. If I give you the symbol can you tell me the name? Vice versa? Pg 17
7. Periods on the periodic table run left to right horizontally (like a sentence that
ends in a period) pg 17-18
8. Groups: are the vertical columns on the periodic table. The elements within
groups are similar in the chemical properties because the have the same outer
orbital and bonding abilities. Pg 17-18
a. Example: Lithium has one outer/valence electron (orbital/period 2) and
Sodium has one outer/valence electron (orbital/period 3). Both are in
group 1.
9. Accuracy: refers to the closeness of the measurement to the correct or accepted
value. Pg 44
a. How close to bulls eye can you throw a dart?
10. Precision: refers to closeness of a set of measurements of the same quantity made
if the same way. Pg44
a. How many times can you throw a dart in the bottom right section?
11. percent error= value experimental – value accepted x 100 pg 45
Value accepted
12. sigfigs: table 5 page 47
13. Density: is a ratio of mass and volume, “Does it sink or does it float?” density of
water is 1.0 g/ml
a. D= m pg 38
v
b. Acceptable units for density include: g/cm3 , kg/m3, g/ml
c. 1 ml = 1 cm3
d. 1000g = 1 kg
e. 1000ml = 1L conversions pg 40
14. Atomic theory --pg 67 beginnings…
a. 2000 years old
b. John Dalton and is 5 statements, pg 68 (isotopes hadn’t been discovered in
Dalton’s time and atoms do vary in physical properties, mass)
15. Current atomic LAWS……. Pg 67
a. Law of conservation of Mass: Mass is neither created nor destroyed during
normal chemical and physical changes (Dalton didn’t describe/clarify normal
circumstances, matter can be created and destroyed in nuclear reactions)
b. Law of Definite Proportions: the fact that a chemical compound contain exactly
the same elements in exactly the same proportions in exactly the same way regardless of
the size of the sample or its source. (salt, NaCl, is the same whether it comes from Salt
Lake City, Utah or the Dead Sea)
c. Law of Multiple Proportions: if two or more different compounds are
composed of the same elements, the ratio of the masses of the second element combined
with a certain mass of the second is always a ratio of small whole numbers. (There
cannot be a half of an atom in a compound. H2O for example is 2:1)
16. Discovery of the electron: Thompson used a Cathode Ray Tube…pg 72
17. Discovery of the atomic nucleus: Rutherford used the Gold foil experiment. Pg 74
a. Alpha particles were aimed a thin piece of gold foil and MOST of them
moved straight through the material without obstruction….this showed
that
i. The nucleus is EXTREMELY SMALL!!!
ii. But contain MOST of the mass
iii. The atom is composed of MOSTLY empty space (doesn’t that
blow your mind?)
18. Electron: The region that electrons (e-) occupy is thought of as an electron cloud
pg 76
19. The nucleus is composed of the neutrons (no) and Protons (p+)
20. Atomic number (Z) of an element is the number of protons of each atom of that
element. This number never changes…it is the address of the element Pg 77
21. Mass Number is the number of proton and neutron of an atom of an element. This
number can vary in atoms of the same element.
22. Atoms with varying Mass Numbers are called ISOTOPES of that element and
have additional neutrons, therefore have a greater mass than the standard atom of
an element. Pg 77-78
23. Isotopes use nuclide symbols. A nuclide is a general term for a specific isotope of
a element
b. Hydrogen-2
c. H-2
2
d.
H
1
24. Calculating the numbers of subatomic particles in a given atom; Table 3 pg 79
e. #n0 ; Mass number – atomic number = number of neutrons
f. #p+ ; is defined as the atomic number; whole number above the symbol on
the period table or the smaller whole number on the bottom left of a
nuclide symbol.
g. #e- ; In an atom without charge (standard atoms and isotopes) # e- = # p+
25. Temperature
h. Convert Fahrenheit to Celsius, C to F, K to C and C to K
i. oC = (F – 32) 5/9
ii. F = C 9/5 +32
iii. K = C + 273
iv. C = K- 273
26. Specific Heat: pg 532
i. Defined as the amount of energy required to raise 1g of a substance by 1
degree C or K 9 (because the size of the degree division on both scales are
equal)
j. Cp = q / (mΔT)
i. q= energy expressed in the units of joules or calories
ii. m= mass express in the units of g or kg
iii. ΔT = change in temperature (temperature final – temperature
initial) expressed in the units of Celsius or Kelvin. Remember
ΔT oC = ΔT K
27. Can you solve for energy required (+q) or lost (-q)? Can you solve for mass (m)
and change in temperature (ΔT)? Remember Cp (specific heat is NEVER a
negative value)
28. Nuclear Chemistry…ch 21 pg 681
a. Fusion: The combination of smaller molecule into larger ones. This
happens on the sun.
b. Fission: The splitting of large molecules into smaller radioactive daughter
isotopes (“Mean Girls”) we do this in nuclear reactor and bombs!
c. The big picture….both nuclear reaction result in the release of LARGE
amount of energy
29. Mass decay: don’t worry about the math… just the concept.
a. When atoms are formed they decrease in mass (What? How is that
possible Ms. Hill, we just learn that matter is conserved?) Conservation of
mass is under ordinary changes, nuclear reactions are extraordinary…
30. What happens to the loss of mass in the formations of atoms?
a. Einstein had it right e=mc2 this famous equation finally means something
to you…. This lost mass is converted into energy and thus when atoms
form energy is release.
GOOD LUCK AND HAVE A GREAT WEEKEND!!!!!