The picture shows a statue of Abraham Lincoln Your friend tells you the statue made of marble. What test could you perform to see if your
friend is correct?
A. Place a drop on water of the statue and see if it evaporates.
B. Rub your hand across the statue and see if it changes colors.
C. Rub water across the surface of the statue and see if it leaves streaks.
D. Place a drop on vinegar of the statue and see if it bubbles.
A mineral break into flat surfaces as shown.
Rocks, Minerals, and Soil
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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.