9 23 When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical
substitution.
In a propagation step a free radical X. is formed.
CH3
CH, CH, -C-CH3 + Cl• → X• + HCI
N
CHE
How many different structures of X• are possible?
A 2
B 3
C 4
D 5

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.  

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?