A. NO2 because the elements are both nonmetals.
A nucleus is in the center of an atom and protons and neutrons are found inside there
fourth period
The third period is similar to the second, except the 3s and 3p sublevels are being filled. Because the 3d sublevel does not fill until after the 4s sublevel, the fourth period contains 18 elements, due to the 10 additional electrons that can be accommodated by the 3d orbitals.
The initial temperature of the water that resulted in the final temperature of the water-metal mixture is 20.7 ⁰C.
<em>"Your question is not complete, it seems to be missing the following information;"</em>
the specific heat capacity of the metal is 0.45 J/g⁰C.
The given parameters;
- <em>mass of water, </em>
<em> = 45 g</em> - <em>final temperature of the water, </em>
<em> = 22 ⁰C</em> - <em>mass of the metal, m = 8.5 g</em>
- <em>initial temperature of the metal, t = 82 ⁰C.</em>
- <em>specific heat capacity of the metal, c = 0.45 J/g⁰C.</em>
The initial temperature of the water will be calculated by applying the principle of conservation of energy;
<em>heat gained by water = heat lost by metal</em>


where;
<em>is the specific heat capacity of the water = 4.184 J/g⁰C.</em>
<em />
<em>Substitute the given values;</em>
45 x 4.184 x (22 - t) = 8.5 x 0.45 x (85 - 22)
4142.16 - 188.28t = 240.98
188.28t = 4142.16 - 240.98
188.28t = 3901.18

Thus, the initial temperature of the water that resulted in the final temperature of the water-metal mixture is 20.7 ⁰C.
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