This scientist passed electric current through gasses and as a result discovered the electron.
J.J. Thompson
100
All atoms of the same element have the same ____.
# of protons
100
____________ of the same element have different numbers of neutrons and therefore different _________.
Isotopes, masses.
100
What does the number 84 in the name krypton-84 represent?
The mass number
200
This scientist confirmed the existence of the neutron.
James Chadwick
200
How much is one atomic mass unit? (Be specific)
1/12th of the mass of a Carbon atom.
200
What is the mass number for an oxygen atom that has 10 neutrons in its nucleus?
18
200
What is the atomic number for an element with 41 neutrons and a mass number of 80?
39
300
This scientist's experiment involved observing the behavior of alpha particles as they hit a piece of gold foil.
Ernest Rutherford
300
Identify the location of the each subatomic particle. Which particle takes up most of the space of an atom?
Nucleus contains protons and neutrons.
The electrons are outside the nucleus and take up most of the volume of an atom.
300
How many protons are present in an atom of Be-9?
4
300
List the number of protons, neutrons, and electrons in Carbon 13.
Protons - 6
Electrons - 6
Neutrons - 7
400
This scientist was the first to suggest the existence of atoms.
Democritus
400
How did Dalton's methods differ from Democritus'?
Democritus' ideas did not explain chemical behavior. His ideas lacked experimental support. Dalton used the scientific method to guide his research and his theory had experimental support.
400
Why are the atomic masses of elements not whole numbers if the mass of protons and neutrons are both whole numbers?
The atomic mass is the weighted average of the masses of its isotopes.
400
Consider an element Y that has two naturally occurring isotopes with the following percent abundances: the isotope with a mass number of 19.0 is 45.0% abundant; the isotope with a mass number of 21.0 is 55.0% abundant. What is the average atomic mass for element Y?
20.1 amu
500
This scientist carried out experiments to find the quantity of charge carried by an electron.
Robert Millikan
500
What are the 4 parts to Dalton's Atomic Theory?
1. All elements are made of atoms - which are indivisible
2. Atoms of the same element are identical
3. Atoms mix or combine in whole # ratios
4. Chemical reactions can join, separate, or rearrange atoms but can't change them.
500
What are the three particles that make up the atom. Identify their relative mass and charge.
Neutron - mass of 1, no charge
Proton - mass of 1, positive charge
Electron - mass 1/1840 of a proton, negative charge
500
Identify the element that has the following isotopes. The first isotope has a mass of 78.92 amu and an abundance of 50.69% The second isotope has a mass of 80.92 and an abundance of 49.31%. Use math to support your answer.