an atomic physicist determines that an atom is composed of 8 positively charged particles and has a mass of…
an atomic physicist determines that an atom is composed of 8 positively charged particles and has a mass of 15 amu. which is the best conclusion that can be drawn?\no the atom has 7 neutrons and 8 protons.\no the atom has 7 electrons and 8 protons.\no the atom has 8 neutrons and 7 electrons.\no the atom has 8 electrons and 7 protons.
Answer
Answer:
A. The atom has 7 neutrons and 8 protons.
Explanation:
Step1: Identify positively - charged particles
Protons are positively - charged. Given 8 positively - charged particles, so number of protons $p = 8$.
Step2: Recall mass number formula
The mass number $A$ of an atom is the sum of protons and neutrons, $A=p + n$, where $A$ is mass number, $p$ is number of protons and $n$ is number of neutrons.
Step3: Calculate number of neutrons
Given $A = 15$ and $p = 8$. Substitute into formula: $n=A - p$. So $n=15 - 8=7$. Electrons are not considered in mass calculation and are negatively - charged. So the atom has 7 neutrons and 8 protons.