What three subatomic particles comprise every atom of every element (except hydrogen)?
Protons, Neutrons, & Electrons
100
Calculate the number of protons, electrons, and neutrons in an atom of Pb with a mass of 207 and an atomic number of 82.
Protons: 82, Electrons: 82, Neutrons: 125
100
How many protons are in a hydrogen atom?
1
100
Why are atomic masses not whole numbers?
Because they are a weighted average of the various isotopes' masses based on the percent contribution of each
100
amu
Atomic Mass Unit
200
Which subatomic particles can be found in the nucleus of an atom according to the modern understanding of atoms?
Protons and neutrons
200
What makes the different isotopes of an element different?
Neutrons or mass
200
How many electrons are in a hassium atom?
108
200
What subatomic particles contribute to an atoms mass?
Protons and neutrons
200
What is a beta particle?
A radioactive particle not unlike an electron
300
Which scientist described the existence of the neutron?
Chadwick
300
Phosphorous has an isotope that weighs 32 amu's. How many neutrons are in its nucleus?
17
300
How many neutrons are in a radon atom?
136
300
Where is the amu derived from?
it is 1/12th the mass of the nucleus of a carbon-12 atom.
300
What is an alpha particle?
A radioactive particle not unlike the nucleus of a helium-4 atom
400
Which scientist described an atom made of a solid positively charged substance with electrons dispersed throughout?
Thomson
400
How many protons are in the nucleus of a Carbon-14 atom?
6
400
A barium isotope has 83 neutrons. What is its mass?
139 amu
400
An element X has three naturally occurring isotopes: X-24, X-25, and X-26. X-25 has a mas of 24.986 and has a percent contribution of 10%. X-26 has a mass of 25.982 and has a percent contribution of 11.01%. Given that the weighted atomic mass of element X is 24.305, what is the percent contribution of X-24 to the overall atomic mass of element X?
78.99%
400
What is an isotope?
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties
500
Which scientist described a positively charged core in the middle of a lot of empty space?
Rutherford
500
Carbon has 3 isotopes: 12, 13, and 14. Which one is the most abundant?
12
500
This atom has an atomic mass of 56 and contains 30 neutrons. What is it?
Iron
500
An element X has two naturally occurring isotopes: X-79 (abundance = 50.69%, mass = 78.918 amu) and X-81 (abundance = 49.31%, mass = 80.917amu). Calculate the weighted atomic mass of element X and identify it.