What role does water play in a nuclear power plant? Select all that apply. The metal rods holding the nuclear fuel pellets are stored in a pool of water, which absorbs the neutrons produced and controls the rate of the nuclear reactions.
Liquid water absorbs some of the heat of the reaction, which helps to control the reactions.
Water chemically reacts with uranium, which causes uranium to emit neutrons and produce a chain reaction.
Liquid water is boiled to steam, which is pressurized and turns the turbine to produce electricity.

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.

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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.  

answer carbon and three oxygen atoms;

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.