2 Answers

Diabetesjones · Answer 1 · 2021-10-13T01:36:39+0000

Answer:

$\boxed {\boxed {\sf A. \ _\text{19}^\text{39}\text{X}^(+) }}$

Step-by-step explanation:

Isotope notation is written as:

$_\text{Z}^\text{A}\text{X}$

where A is the mass number and Z is the atomic number. A charge can be added to the right subscript if needed.

1. Find A

A is the mass number, or the sum of protons and neutrons.

There are 19 protons and 20 neutrons.

2. Find Z

Z is the atomic number of number of protons.

There are 19 protons.

3. Find a possible charge

If this is a neutral atom, the protons equal the neutrons.

There are 19 protons and 18 electrons, which is obviously not equal. This is an ion and there is a charge.

There is 1 more proton. A proton has a positive charge, so the charge must be +1.

4. Write the symbol.

A= 39, Z= 19, and the charge is +1

$_\text{19}^\text{39}\text{X}^(+1)$

So, the correct answer must be choice A.

Please log in or register to add a comment.