Question

2 points

In the element.  ³⁹19K the number of neutrons is —-.

39

19

20

58

​

Answer 1

Explanation:

The free neutron has a mass of 939,565,413.3 eV/c2, or 1.674927471×10−27 kg, or 1.00866491588 u. The neutron has a mean square radius of about 0.8×10−15 m, or 0.8 fm, and it is a spin-½ fermion.

Mass: 1.67492749804(95)×10−27 kg; 939.56542052(54) MeV/c2; 1.00866491588...

Electric charge: 0 e; (−2±8)×10−22 e (experimental limits)

Electric polarizability: 1.16(15)×10−3 fm3

Spin: 1/2

Answer 2

Answer:

39

Explanation:

The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).