Answer: Sodium + water → hydrogen gas + sodium hydroxide (aq) + heat [(aq) means “dissolved in water”. It stands for “aqueous”.] If we boil off the water, we will be able to see the sodium hydroxide crystals. The sodium hydroxide is one of the two new substances produced by this chemical change.
Answer:
When radioactive atoms decay, they release energy in the form of ionizing radiation (alpha particles, beta particles and/or gamma rays). The energy is called ionizing radiation because it has enough energy to knock tightly bound electrons from an atom's orbit. This causes the atom to become a charged ion
<u>Given:</u>
Mass = 68 kg
Power = 65 W
<u>To determine:</u>
Calories burned during an 8.0 hr sleep
<u>Explanation:</u>
Energy is expressed as:
Energy = Power * Time
Now, the unit of power = Watt (W)
1 W = 1 J/s i.e. 65 W = 65 J/s
Time = 8 hrs = 8 * 3600 s = 28800 s
Energy = 65 J/s * 28800 s = 1872000 J
Convert Joules (J) to calories (cal)
1 cal = 4.184 J
The calculated energy = 187200 J * 1 cal/4.184 = 447418 cal
Ans: The man burns nearly 447.4 kcal during an 8 hr sleep