Atomic Structure
Which subatomic particle has a negative charge and is found outside the nucleus?
Which Greek philospopher proposed that matter was made of tiny, indivisible particles called atomos?
Democritus
What are atoms of the same element with different numbers of neutrons called?
Isotopes
In nuclear notation, this number appears at the lower left of the element symbol and tells you the number of protons.
The atomic number
What is 5,600 in scientific notation?
5.6 X 103
Which 2 subatomic particles are locate in the nucleus? What are their respective charges?
Neutron- neutral
Proton- positive
Which scientist proposed that atoms of each element were identical and compounds formed in fixed ratios and were a solid, indivisible spheres?
John Dalton
Chlorine-35 has 17 protons. How many neutrons does it have?
18
Write the nuclear notation for an atom of carbon with 6 protons and 8 neutrons.
146C
*sorry formatting is weird*
What is 0.00072 in scientific notation?
7.2 X 10-4
What identifies what type of element an atom is?
How is an amu defined?
The atomic number- the number of protons
Atomic mass unit- 1/12 of a carbon-12 atom.
Which scientist experimented with a cathode-tube that led to the discovery of the electron and his "plum pudding" model?
J. J. Thomson
An element has two isotopes: 10.0% has a mass of 10 amu and 90.0% has a mass of 11 amu. Calculate its average atomic mass to the correct number of sig figs.
10.9 amu
Identify the number of protons, neutrons, and electrons in a neutral atom of 2311Na?
*sorry for weird formatting*
Protons-11
Neutrons-12
Electrons-11
What is 3.05 X 106 in standard form?
3,050,000
An atom has 17 protons, 18 neutrons, and 17 electrons. What is its mass number? Include units.
35 amu
In the gold foil experiment, most alpha particles passed through the foil, but a few bounced back. What did this reveal? And who was the scientist?
Ernest Rutherford- this revealed that atoms are mostly empty space with a tiny, dense, positively charged nucleus.
An element has isotopes of 24 amu (80.0%) and 26 amu (20.0%). Calculate its average atomic mass to the correct number of sig figs.
24.4
What is the isotope notation for a chlorine atom with 17 protons, 19 neutrons, and 17 electrons?
Chlorine-36
Using dimensional analysis, how many centimeters are in 2.5 meters? Calculate to the correct number of sig figs.
250 cm
Barium has an atomic number of 56 and an atomic mass of 137.33 amu. How many protons, neutrons, and electrons are there in a Barium atom?
Protons- 56
Electrons- 56
Neutrons- 81
What is the difference between Bohr's model and the Quantum Mechanical Model?
Bohr's model said that electrons travel in specific orbits (energy levels) around the nucleus and can jump to and fall back to different energy levels. The Quantum Mechanical Model said that there is an electron cloud and describes electrons using probability distributions called orbitals.
An element has two isotopes with masses of 10.0 amu and 11.0 amu. Its average atomic mass is 10.8 amu. What is the percent abundance of the heavier isotope?
80.0%
A nucleus of an Iron atom contains 26 protons and 30 neutrons. Write it in both nuclear and isotope notation.
Isotope Notation- Iron-56
Nuclear Notation- 5626Fe
*Sorry for the weird formatting*
Convert 72.0 km/h to meters per second to the correct number of sig figs.
Use 1 km=1 X 103 m and 1 h=3.6 X 103 s
20.0 m/s