Question

atom a has an atomic number of 20 and mass number of 41. atom b has an atomic number of 19 and a mass number of 40. which of these is an accurate statement? atom a has one less proton and one more neutron than atom b. atom a has an extra nucleon compared to atom b. atom a has one more proton and one more electron than atom b. atom a has more protons than atom b.

Explanation:

The atomic number is equal to the number of protons. Atom A has atomic number 20 and Atom B has atomic number 19, so Atom A has one more proton than Atom B. In a neutral atom, the number of electrons is equal to the number of protons. So Atom A also has one more electron than Atom B. The mass number is the sum of protons and neutrons. Atom A has mass - number 41 (20 protons + 21 neutrons) and Atom B has mass - number 40 (19 protons + 21 neutrons).

Answer:

Atom A has one more proton and one more electron than Atom B.