Early Atomic Ideas
This scientist proposed that all matter is made of tiny particles called atoms.
Who is John Dalton?
This subatomic particle has a positive charge and is found in the nucleus.
What is a proton?
This number tells you the number of protons in an atom.
What is the atomic number?
This type of radiation consists of two protons and two neutrons.
What is alpha radiation?
An atom has 8 protons and 8 neutrons. What is its mass number?
What is 16?
This scientist proposed the plum pudding model of the atom.
Who is J. J. Thomson?
This subatomic particle has a negative charge and is found outside the nucleus.
What is an electron?
This number is the sum of the protons and neutrons in an atom’s nucleus.
What is the mass number?
This type of radiation consists of a high-energy electromagnetic wave and has no mass or charge.
What is gamma radiation?
A neutral atom has an atomic number of 12 and a mass number of 24. How many electrons does it have?
What is 12?
This scientist proposed the plum pudding model of the atom.
Who is J. J. Thomson?
Using the periodic table, identify the element that has 12 protons.
What is magnesium (Mg)?
Two atoms of the same element have different numbers of neutrons. They are called these.
What are isotopes?
This type of radiation involves a high-speed electron emitted from the nucleus.
What is beta-minus radiation?
A neutral atom has 15 protons and a mass number of 31. How many neutrons does it have?
What is 16?
In this experiment, alpha particles were directed at thin gold foil, revealing that atoms contain a small, dense nucleus.
What is Rutherford’s gold foil experiment?
An ion has 13 protons, 14 neutrons, and 10 electrons. Identify the element, its mass number.
What is aluminum-27
Write the nuclear (symbol) notation for an isotope with 11 protons and 12 neutrons.
Rank alpha, beta, and gamma radiation from lowest to highest penetrating ability.
Alpha, beta, gamma.
An element has two isotopes: 10 amu at 20% abundance and 11 amu at 80% abundance. Calculate its average atomic mass.
What is 10.8 amu?
According to Dalton’s original atomic theory, atoms of the same element were thought to be identical in mass. The discovery of these showed that idea was not entirely correct.
What are isotopes?
An ion has a mass number of 40, 18 electrons. Using the periodic table, identify the element and determine its numbers of protons and neutrons.
What is calcium (Ca), with 20 protons and 20 neutrons?
For 3717Cl, determine the numbers of protons, neutrons, and electrons.
17 protons, 20 neutrons, 18 electrons.
During alpha decay, an atom’s mass number decreases by 4 and its atomic number decreases by 2. If uranium-238 undergoes alpha decay, what isotope forms?
What is thorium-234?
An element has two isotopes: 35 amu at 75% abundance and 37 amu at 25% abundance. Calculate its average atomic mass.
What is 35.5 amu?