Question

question 1 1 pts which element has 9 protons? beryllium potassium fluorine question 2 1 pts an atom has 19 protons and 20 neutrons. what is the mass?

Explanation:

Step1: Recall atomic number concept

The atomic number of an element is equal to the number of protons. Fluorine has an atomic number of 9, so it has 9 protons.

Step2: Recall mass - number formula

The mass number of an atom is the sum of the number of protons and neutrons. Given 19 protons and 20 neutrons, the mass number is \(19 + 20=39\).

Answer:

Question 1: C. fluorine
Question 2: 39