Atomic Structure
This particle has a positive charge and is found in the nucleus of an atom.
What is a proton?
The number of protons in an atom determines this atomic characteristic.
What is atomic number?
This is the average mass of atoms of an element, taking into account isotopes.
What is average atomic mass?
This number, 6.022 × 10²³, represents the number of atoms or molecules in one mole of a substance.
What is Avogadro’s number?
This law states that matter is not created or destroyed in chemical reactions.
What is the law of conservation of mass?
This term refers to atoms of the same element with different masses due to varying numbers of neutrons.
What are isotopes?
This is the total number of protons and neutrons in the nucleus of an atom.
What is mass number?
If carbon has 3 isotopes, carbon-12, carbon-13, and carbon-14, this is the most abundant isotope.
What is carbon-12?
This is the mass found on the periodic table that is equal to one mole of that element.
What is molar mass?
This law states that a compound always contains the same elements in the same proportion by mass.
What is the law of definite proportions?
This experiment led to the discovery of the nucleus after some alpha particles were deflected.
What is Rutherford's gold foil experiment?
This is a charged atom that has more electrons than it does protons.
What is an anion?
If an element has a 50% abundance at a mass of 106.96 amu and 50% abundance at a mass of 108.96 amu, this is the element and average atomic mass.
Silver, 107.96
This is molar volume.
What is 22.4 L/mol?
This law describes how two elements can combine to form different compounds in small whole-number ratios. (e.g. CO, CO2)
What is the law of multiple proportions?
The particle discovered by JJ Thompson in 1897 through cathode-ray experiments.
What is the electron?
p+ = 77, n0 = 117, e- = 77
What are the protons, neutrons, and electrons for:
Element name: iridium
atomic #: 77
mass #: 194 amu
Iodine has three natural isotopes. This is the average atomic mass of iodine if iodine-126 has a 17% abundance, iodine-127 has a 80% abundance, and iodine-128 has a 3% abundance. Show your work!
AAM = 126(0.17) + 127(0.80) + 128(0.03)
AAM = 21.42 + 101.6 + 3.84
AAM = 126.86 amu
How many moles are in 263.9 g of lead? Show you work!
What is 1.274 moles Pb? (4 sig figs)
263.9 g Pb x 1 mol Pb = 1.2736486 mol Pb
1 207.20 g Pb
According to this theory, only whole numbers of atoms can combine to form compounds.
What is Dalton’s atomic theory?
The attraction that holds protons and neutrons together in the nucleus.
What are nuclear forces?
These are the protons, neutrons, and electrons from the following:
12050Sn2+
What is the nuclear notation of
p+ = 50, n0 = 70, e- = 48
An element has 3 natural isotopes. Their % abundance and relative mass are as follows:
78.70% and 23.985 amu
10.13% and 24.986 amu
11.17% and 25.983 amu
This is the element and average atomic mass. Show your work!
AAM = 23.985(0.7870) + 24.986(0.1013) + 25.983(0.1117)
AAM = 18.8762 + 2.5311 + 2.9023
AAM = 24.31 = Magnesium
What is 7.46 x 1023 atoms of Si?
34.8 g Si x 1 mol Si x 6.022 x 1023 atoms Si =
1 28.09 g Si 1 mol Si
This Greek philosopher said all matter is made up of basic particles, atoms, which are indivisible.
Who is Democritus?