A geologist is studying layers of rock. He finds a fossil with an imprint of a shelled animal. According to the law of faunal and floral succession, what kind of fossil would he most likely find next, in the layer of rock above it? Look back to the Fossil Succession Chart for help.

a fossil of amphibians
a fossil of reptiles
a fossil of fishes
a fossil of humans

A fossil of fishes

Explanation:

Right after fossils of shells, fossil of fishes appear, according to a Fossil Succession Chart.

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.