What is the energy change when a 777.1 g sample of water has an initial temperature of 57.3 °C and a final temperature of
42.6 °C

 -47749.69 joule energy release.

Explanation:

Given data:

Mass of water = 777.1 g

Initial temperature = 57.3°C

Final temperature = 42.6 °C

Energy change = ?

Solution:

Specific heat capacity of water is 4.18 J/g.°C

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 42.6 °C - 57.3°C

ΔT = -14.7°C

Q = 777.1 g × 4.18J/g.°C ×  -14.7°C

Q =  -47749.69 J

 -47749.69 joule energy release.

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.