Atoms and Elements
1. Put the letter of the correct answer in the blank. Recall that the / symbol means per and the symbol # means number. For example, # cents/dollar reads: number of cents per dollar.
Mass number _____
Atomic number _____
Isotopes of one element _____
Radioactive element _____
Periodic table _____
a) # protons/nucleus
b) # protons and neutrons/nucleus
c) # protons same, # neutrons differ
d) arranged by # protons/nucleus
e) nuclei break down
2. Find the chemical symbols and atomic numbers of these elements:
3. The mass number of a uranium isotope is 238. How many protons, neutrons, and electrons in each atom?
4. An atom of a radioactive isotope of carbon changes by losing one proton. What "new" element is produced by this change?
5. If an atom of thorium loses 2 protons, what element would be left?
6. If a nitrogen nucleus gains 1 proton, what element would result?
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