Question

Part 1: Name two elements that have the same properties as calcium (Ca) (4 points)
Part 2: Determine the number of protons, electrons, and neutrons present in an atom of calcium (Ca). Explain how you determined your answer using complete sentences. (6 points)

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Answer Template:

Part 1: Two elements that have the same properties as calcium (Ca) are:

1.

2.

Part 2: Calcium (Ca) has the following number of protons, electrons, and neutrons:

# protons =
This is how I determined the number of protons:
# electrons =
This is how I determined the number of electrons:
#neutrons=
This is how I determined the number of neutrons:

Answer 1

Part 1: Two elements that have the same properties as calcium (Ca) are:

1. Magnesium (Mg)

2. Strontium (Sr)

Part 2: Calcium (Ca) has the following number of protons, electrons, and neutrons:

# protons = 20
This is how I determined the number of protons: The atomic number of calcium on the periodic table is 20, and the atomic number equals the number of protons in an atom.

# electrons = 20
This is how I determined the number of electrons: A neutral calcium atom has the same number of electrons as protons, so it has 20 electrons.

# neutrons = 20
This is how I determined the number of neutrons: The most common isotope of calcium is calcium-40 (mass number ≈ 40). Neutrons = mass number − atomic number, so 40 − 20 = 20 neutrons. (Alternatively, the atomic mass 40.08 is rounded to the nearest whole number 40 to find the mass number.)