Laws & Theories
1) What is the Law of Conservation of Mass?
2) Who proposed this law?
1) Mass is neither created nor destroyed
2) Antoine Lavoisier
What are the charges of the following subatomic particles? Also note down where they are located.
1) Proton
2) Neutron
3) Electron
1) Positive
2) Neutral
3) Negative
1) Which chemist first discovered the electron?
2) what experiment did they use to discover the electron?
1) J.J. Thomson
2) Cathode Ray Tube experiment (He drew out the electrons using the Plum Pudding Model)
Identify whether all 5 atoms/compounds are cations, anions, or neutral.
1) O2-
2) CO3+
3) Na+
4) Si
5) P3-
1) Anion
2) Cation
3) Cation
4) Neutral
5) Anion
How many protons and neutrons are present in the following Carbon isotopes?
1) A = 12; Z = 6
2) A = 13; Z = 6
3) A = 14: Z = 6
1) P = 6; N = 6
2) P = 6; N = 7
3) P = 6; N = 8
Joseph Proust proposed the _______________ which states _________________________________.
1) Law of Definite Proportions
2) A compound will always contain the exact same proportion of elements by mass
What is the formula to determine the atomic mass of an element?
Atomic Mass = Protons + Neutrons
Who is known as the 1st chemist?
How many electrons, protons, and neutrons does the following element have?
Ag
A = 107.87; Z = 47
Electrons = 47
Protons = 47
Neutrons = ~ 60
Identify the following information for isotope: Boron-11
1) Atomic Number
2) Mass Number
3) Number of Protons
4) Number of Neutrons
5) Number of Electrons
1) 5
2) 11
3) 5
4) 6
5) 5
Provide all 4 statements of Dalton's Atomic Theory.
1) Each element is made up of atoms
2) Atoms of a given element are identical
3) Chemical compounds are formed when atoms of different elements combine with each other
4) Chemical reactions involve reorganizing atoms
Which of the following particles adds up to the same number as the atomic number of an element?
A) Neutrons + Protons
B) Protons + Electrons
C) Protons
D) Neutrons
E) Neutrons + Electrons
C) Protons
Provide an answer to all 3 questions:
1) Who discovered the Nuclear Atom? What experiment was used to discover this?
2) What happened to the alpha particles in the Gold Foil Experiment?
3) Due to what happened to the alpha particles, what was found during the Gold Foil Experiment?
1) Ernest Rutherford; Gold Foil Experiment
2) Rutherford believed that the alpha particles shot towards the gold foil would pass through. However, the alpha particles bounced back.
3) Since the alpha particles bounced back (due to being positively charged), it was apparent to Rutherford that the nucleus was positively dense. *Just like magnets, opposites attract!
How many electrons, protons, and neutrons does the following element have?
Ca2+
A = 40.078; Z= 20
Electrons = 18
Protons = 20
Neutrons = ~ 20
Which of Dalton's Atomic Theories (1808) does the idea of Isotopes debunk?
"The atoms of a given element are identical"
What was Avogadro's Hypothesis, and what is the value of Avogadro's number?
Hypothesis = Equal volumes of different gases contain the same number of particles at the same temperature and pressure.
Avo's # = 6.022 x 1023 atoms in 1 mole of an element
What are the diatomic atoms?
(Name them all)
H2 (Hydrogen)
N2 (Nitrogen)
F2 (Fluorine)
O2 (Oxygen)
I2 (Iodine)
Cl2 (Chloride)
Br2 (Bromine)
Provide an answer for the 2 questions:
1) What did Robert Millikan find (looking for specifics ~ such as value)?
2) What experiment/method did he use to find this discovery?
1) He found the mass and charge of an electron (9.11 x 10-3 kg)
2) He used the Oil Drop Experiment
How many electrons, protons, and neutrons does the following element have?
N3-
A = 14.007; Z = 7
Electrons = 10
Protons = 7
Neutrons = ~7
Identify the following information for isotope:
Uranium-235
1) Atomic Number
2) Mass Number
3) Number of Protons
4) Number of Neutrons
5) Number of Electrons
1) 92
2) 235
3) 92
4) 143
5) 92
What is Boyle's Law (what did he contribute)?
He quantified the relationship between pressure and the volume of air
A neutral hydrogen atom can have at most __________ electron it its valence when it makes a bond with non-metals.
1
*A neutral hydrogen atom has no charge meaning there are the same number of protons and the same number of electrons. Hydrogen only has 1 proton. Anymore and we would be talking about a different element.
1) Radioactivity was discovered by __________________.
2) In this discovery, three types of particles were discovered. What are the three types of particles and what charges do each carry?
1) Henri Becquerel
2) Alpha = Positive (2 Protons + 2 Neutrons); Beta = Negative (1 electron); Gamma = Neutral (pure electromagnetic energy)
Identify the following element/ion/isotope. (Write the answer out in the A & Z formation)
Protons = 30
Electrons = 28
Atomic Mass = 66
Zinc Cation (Zn2+)
A = 66
Z = 30
Identify the following information for isotope:
Cd-111
1) Atomic Number
2) Mass Number
3) Number of Protons
4) Number of Neutrons
5) Number of Electrons
1) 48
2) 111
3) 48
4) 63
5) 48