Atomic Structure
Which subatomic particles have a mass of 1 amu?
Protons and neutrons
Who theorized that atoms are small, indivisible spheres?
John Dalton
Fill in the blanks:
Isotopes have the same ______ and different ______.
-same (atomic number or number of protons)
-different (mass number or number of neutrons)
How does the number of neutrons differ between the isotopes Cl-37 and Cl-35?
Cl-37 has two more neutrons
What is the mass number of an atom that has 8 protons, 8 electrons, and 9 neutrons?
17 amu
What is one discovery of Rutherford's gold foil experiment?
-atoms are mostly empty space
-atoms contain a small, dense, positively charged nucleus
Which notations represent isotopes of neon?
a. 1020Ne and 1020Ne
b. 921Ne and 1020Ne
c. 1020Ne and 1021Ne
d. 920Ne and 1020Ne
c. 1020Ne and 1021Ne
What is the charge of an ion that has 7 protons and 10 electrons?
-3
What is the charge on the nucleus of a barium atom?
+56
Which subatomic particle was discovered by the cathode ray experiment?
The electron
If the average atomic mass of nitrogen is 14.0067, then what is the most abundant isotope of nitrogen?
Nitrogen-14
What is one discovery from the Bohr model of the atom?
Atoms are located in shells which orbit the nucleus.
How many neutrons does an atom of Cl-37 have?
20 neutrons
Which discovery occurred first?
a. Electrons have wave like qualities and are located in orbitals.
b. Atoms contain small, negatively charged particles.
a. Electrons have wave like qualities and are located in orbitals.
Calculate the atomic mass of lithium to the nearest hundredth place based on the following isotopes and their percent abundance.
Li-7 92.41%
Li-6 7.59%
6.92 amu
Calculate the average atomic mass of potassium to the nearest hundredth place.
K-39: 93.26%
K-40: 0.01%
K-41: 6.73%
39.13 amu
How many electrons does Ca+2 have?
18 electrons
Describe one difference between the Bohr model of the atom and the wave mechanical model of the atom.
Bohr model: electrons orbit the nucleus in shells
Wave mechanical model: electrons are located in orbitals (electron cloud)
Cl-35: 75.77%, Cl-37-24.23%
Which answer choice shows the correct numerical set up for determining the atomic mass of chlorine?
a. (35 u)(75.77) + (37 u)(24.23)
b. (35 u)(0.7577) + (37 u)(0.2423)
c. (35 u)(0.2423) + (37 u)(0.7577)
d. (35 u)(24.23) + (37 u)(75.77)
b. (35 u)(0.7577) + (37 u)(0.2423)