Select all that apply. The following diagram shows the path of a planet around the Sun. Kepler discovered that
Time=t
P
-P3
Time=t
P,
Time=t
B
A
D
Ps
Time = 2t
6
20 pesqwere, no
area A = area B
the distance from P2 to P3 is half the distance from Pg to P6
the speed in the interval from P, to P2 is twice the speed in the interval from Po to P
the speed in the interval from P, to P2 is less than the speed in the interval from Pa to P4

a:

by the combination of an unlimited number of elements

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.  

you need to have a picture of the atom that way we can answer it