Question

What is the atomic number of a neutral atom that has five neutrons and four
electrons

Answer 1

9

Step-by-step explanation:

So for berylium, there are 4 protons, 5 neutrons and 4 electrons. But to calculate atomic mass number, 4 electrons won't be counted. Hence the atomic number of berylium will be the sum of 4 protons and 5 neutrons and that will be equal to 9