At room temperature oxygen, 
is present in the gas phase.
A gas is defined as a substance which is characterized by the rapidly movement of molecules which are widely separated. The shape and volume of gas is not definite that is they take on the shape of the container in which it is placed. The gas molecules have minimum inter-nuclear attractions and thus have high kinetic energy.
Thus, the sentences that describes oxygen at room temperature are:
- It has no definite volume and takes the shape of its container.
- Its particles move fast enough to overcome the attraction between them.
- It has more energy than it would be at a cooler temperature as the kinetic energy is directly proportional to the temperature that is kinetic energy increases on increasing the temperature.
Explanation:
A student flips four different coins at the same time. Which choice shows all of the possibilities for the results of the coin toss? (H = heads, T = tails)
A HH, TT, HT, TH
B HHHT, HTTT, HHTT
C HHH, TTT, HTH, HTT
D HHHH, HTHH, HTTH, HTTT, TTTT
Answer:
Option B.
Explanation:
As any reaction of combustion, the O₂ is a reactant and the products are CO₂ and H₂O. Combustion reaction for ethane is:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
So 2 moles of ethane react with 7 moles of oxygen to make 4 moles of dioxide and 6 moles of water.
Then 2 moles of ethane will produce 4 moles of CO₂
The 3d sublevel is not filled until after the 4s sublevel, because the 3d sublevel has more energy than the 4s sublevel, and less energy than the 4p sublevel. (:
For one mole of hydrogen, H, the atomic mass is 1 g per mole. Hydrogen contains 1 proton and zero neuton. A neutral atom of hydrigen also contains 1 electron.
