Question

Please help! 30 points! ASAP plz and correct answers only please!!

Answer 1

Answer: NA and Rb and there are 20 protons in calcium!

Step-by-step explanation:

Answer 2

Answer:

No. of protons = 20

No. of electrons = 20

No. of neutrons = 20

Step-by-step explanation:

Part 1 :

Na, K and Rb are in the same group.

So, K and Rb are the two elements that have the same properties as sodium ( Na ).

Part 2 :

Atomic Number of Calcium = 20

Note :

Atomic Number = No. of protons

Therefore,

No. of protons = 20

Note :

No. of neutrons = No. of protons.

Therefore,

No. of neutrons = 20

Calcium is the 20th element, with 20 protons. Since a stable atom has a net charge of 0, it must have 20 electrons.