Answer:
The octet rule means that atoms need a total of 8 valence electrons to fill their valence shell. Hydrogen only needs two to fill its valence shell.
Explanation:
All atoms except for hydrogen can hold a total of 8 valence electrons in their outer energy levels (2 in the s level, 6 in the p level). Hydrogen only has two electrons total, so it does not require more than the s level and two electrons to have a full valence.
<u>Answer:</u> The temperature increase will be 31.70°C.
<u>Explanation:</u>
To calculate the increase in the temperature of the system, we use the equation:

where,
q = Heat absorbed = 36.5 kJ = 36500J
m = Mass of water = 275 g
c = Specific heat capacity of water = 
= change in temperature = ? °C
Putting values in above equation, we get:

Hence, the temperature increase will be 31.70°C.
<u>Answer:</u> The change in temperature is 84.7°C
<u>Explanation:</u>
To calculate the change in temperature, we use the equation:

where,
q = heat absorbed = 1 kCal = 1000 Cal (Conversion factor: 1 kCal = 1000 Cal)
m = mass of steel = 100 g
c = specific heat capacity of steel = 0.118 Cal/g.°C
= change in temperature = ?
Putting values in above equation, we get:

Hence, the change in temperature is 84.7°C
Answer: C. <em><u>She should decrease the frequency of the wave</u></em>
<em>Explanation: this makes the waves shorter causing it to become louder the the human ear!</em>
<h3><u><em>hope it helps</em></u></h3>