PLS HELP ASAP I WILL GIVE THANKS BUT JUST PLS HELP NOW Earth

What is the orbit of the Earth?
Is the Sun at the center of the Earth’s orbit?
Describe the motion of the Earth throughout its orbit? Does it move at a constant speed?

The orbit of the earth is a ellipse.   Yes.  Yes

Explanation:

i believe the answer is a.

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.