The answer is they follow a patter for valence electrons.
Answer:
You would get 19.969 moles
Explanation:
Answer : 135 grams of sodium has 5.869 moles.
Solution : Given,
Mass of sodium = 135 grams
Molar mass of sodium = 23 g/mole
Formula used :

Now put all the given values in this formula, we get

Therefore, the moles of sodium present in 135 grams of sodium is, 5.869 moles.
The heat cause 300g water temperature increase from 20 to 26 celcius. The heat transferred would be: 300g * (26 °C -20 °C) *4.2 joule/gram °C= 7560J
The unknown substance is added to the water, so its final temperature should be the same as the water. The calculation would be:
7560J= 124g * (100-26)* specific heat
specific heat= 7560J / 124g / 74 °C= 0.8238 J/gram °C