PLS HELP Answer the question below. Use the rubric in the materials for help if needed. Use details to support your answer.
A man started at his house and went to the post office, then to the pet store, and finally home again. What is the average
velocity if this trip took three hours?
Explain how you arrived at your answer.
POST OFFICE
PET STORE
4 miles
3 miles
5 miles

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

un recipient conține 6,4 moli de gaz. gazul hidrogen reprezintă 25% din totalul kilometrilor din container. în cazul în care presiunea totală este de 1.24 atm ceea ce este