Question

1. what is the name of each labeled subatomic particle? a: electron b: proton c: neutron 2. how many protons, neutrons and electrons are in the element above? protons: 4 neutrons: 5 electrons: 4 3. what is the mass number of the element? 4. what is the symbol of the element? how can you tell? 5. what is the charge of the element? how can you tell?

Explanation:

Step1: Recall mass - number formula

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

Step2: Identify number of protons and neutrons

From the previous answers, we know that the number of protons $p = 4$ and the number of neutrons $n=5$.

Step3: Calculate mass number

$A=4 + 5=9$.

Step4: Determine element symbol

The number of protons determines the element. An element with 4 protons is beryllium, and its symbol is $Be$. We know this because the atomic number (number of protons) is unique to each element, and beryllium has an atomic number of 4.

Step5: Determine element charge

The charge of an atom is given by the difference between the number of protons and electrons. Here, the number of protons ($p = 4$) and the number of electrons ($e = 4$). The charge $q=p - e$. So, $q=4-4 = 0$. The element is neutral because the number of positively - charged protons is equal to the number of negatively - charged electrons.

Answer:

1. Mass number: 9
2. Symbol: $Be$. It has 4 protons, and beryllium has an atomic number of 4.
3. Charge: 0. The number of protons (4) equals the number of electrons (4).