Answer:
Hydrogen(H) and Heluim(He)
Explanation:
These are the only two valennce electrons and 1 energy levels.
Answer is: 4)Mass
I really hope this helped you out!!!!
Answer: -
Surface Tension
Explanation: -
Surface tension is cohesive force created as a result of hydrogen bonding, that enables a liquid drop to have a minimum surface area.
Due to it being cohesive, the water top surface is concave in nature, allowing us to hence slightly overfill a glass with water.
Due to surface tension, the surface of water behaves like a stretched membrane, allowing dense objects like a length wise steel needle to float on water.
Thus, the hydrogen bonding in water creates __surface tension__, a cohesive force that enables one to slightly overfill a glass with water or allows denser objects, such as a lengthwise steel needle, to float on water
The question asks average kinetic energy. So it is only related with the temperature. The higher temperature is, the higher kinetic energy is. So the answer is (4).
