4. Under pH indicator paper type, be sure that 0-14 paper is selected. Look at the pH color chart in the Gizmom. This chart allows you to match colors from a 0-14 indicator paper to get a pH value for a substance.
5. Record the data in the table below to collect your pH data,
0 to 14 pH indicator paper
Acidic
kating or noutral?

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.  

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)

c) should be the answer.