Which of the following statements are true? 1. Liquid water expands with increasing temperature above 4°C.
2. Liquid water expands with increasing temperature between 0°C and 4°C.
3. Water contracts as it freezes at 0°C.
4. Solid ice is less dense than liquid water.

weeve

Explanation:

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.