Question

In periodic table 1 to 40 proton and neutron electron and mass number

Answer 1

Answer:

K means potassium. If you Go-ogle “potassium” you will find that it has atomic number Z=19 , which means that it has 19 protons in the nucleus. The superscript “+” means that you’re talking about the positive ion of potassium, which means that one of its 19 electrons (that would make it a neutral atom) has been removed somehow, leaving 18 electrons. The number of protons and neutrons is given by the atomic weight A=40 (the superscript on the left), so if you subtract the atomic number from the atomic weight you get the number of neutrons, N=A−Z= 21.