Question

mass number

1. define mass number:

11.
mass number:
element name:
element symbol:

Explanation:

Step1: Recall mass number formula

Mass number ($A$) is the sum of protons ($P$) and neutrons ($N$), so $A = P + N$.

Step2: Identify $P$ and $N$ values

From the diagram, $P = 38$ and $N = 50$.

Step3: Calculate mass number

Substitute values: $A = 38 + 50 = 88$.

Step4: Determine element from protons

Atomic number ($Z$) equals number of protons ($P = 38$). The element with $Z = 38$ is Strontium (Sr).

Answer:

Mass Number: $\boldsymbol{88}$
Element Name: $\boldsymbol{\text{Strontium}}$
Element Symbol: $\boldsymbol{\text{Sr}}$