What is one way in which chemistry affects your everyday life? A. Refrigerators use energy more efficiently than they did 10 years
ago.
B. Tap water is safe to drink because it is monitored for harmful
substances.
c. Weather forecasts are now more accurate because of radar.
D. Watches are now more accurate because they are digitalized.

B

Explanation: Water is filtered with a bunch of chemicals which makes it drinkable.

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.