Use the portion of the periodic table shown below to answer the questions.

part 1: name two elements that have the same properties as sodium (na). (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)

For 1: The two elements having same properties as sodium are potassium and rubidium.

For 2: Calcium has 20 protons, 20 electrons and 20 neutrons.

Explanation:

The elements which belong to the same group, tend to have same properties. Group represents the vertical row in the periodic table. Hence, the elements which have same properties as sodium are potassium and rubidium.

Atomic number is defined as the number of protons or electrons in an element.

Atomic number = Number of electrons = Number of protons

Atomic mass is defined as the sum of number of protons and neutrons in an element.

Atomic mass = Number of protons + Number of neutrons

Atomic number of calcium is 20. So, number of protons and electrons will be 20.

Atomic mass of calcium is 40.

40 = Number of neutrons + 20

Number of neutrons = 20

Hence, calcium has 20 protons, 20 electrons and 20 neutrons.

the correct answer is:

a. formation of precipitation