Question

pre-ap chemistry bellwork 10/14
answer the following questions:
an atom has a mass or 23 amu and 12 protons. how many neutrons does it have?
write the chemical formula for an atom with 15 protons.
what is an ion?

Explanation:

Step1: Recall mass - number formula

The mass number (A) of an atom is the sum of the number of protons (p) and neutrons (n), i.e., $A=p + n$.

Step2: Calculate number of neutrons

Given $A = 23$ amu and $p=12$. We can find $n$ by rearranging the formula: $n=A - p$. Substituting the values, we get $n = 23-12=11$.

Step3: Identify element by proton number

The number of protons defines the element. An atom with 15 protons is phosphorus, and its chemical symbol is P.

Step4: Define an ion

An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Answer:

• The atom has 11 neutrons.
• The chemical formula for an atom with 15 protons is P.
• An ion is an atom or molecule with a net electrical charge due to the loss or gain of electrons.