- Using the choices below, which is the complete symbol for the isotope that has the following subatomic particles: 19 protons, 21 neutrons, and 18 electrons.
C.
D.
E.
A.
40 -1
B.
40
21
iR-1
33K+1 4.K+1
izArt1
b. B
A
d. D
e. E
с
c.
a.

The elements in nature have several types of isotopes

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.

So Isotopes are elements that have the same Atomic Number (Proton)

The element has : 19 protons, 21 neutrons, and 18 electrons.

atomic mass = protons+neutrons = 19+21=40

atomic number=number of protons=19

charge of elements = protons-electrons = 19-18=+1

The element in the periodic system having the atomic number 19 is K

So symbol of element

the answer would be c

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >