Answer:
Excess Reagent = oxygen
Explanation:
Limiting reagent: The substance that is totally consumed when the reaction is completed.
Excess reagent: The substance left after the limiting reagent is consumed completely
The balanced chemical equation for formation of water is as follow:

This means when 2 moles of hydrogen reacts with 1 mole of oxygen, 2 moles of water is produced.
Hence the ratio in which hydrogen and oxygen gas reacts is 2:1
Now if 2 mole hydrogen require 1 mole of oxygen ,then 4 mole hydrogen need 2 mole of oxygen.

or

Here 5 mole of oxygen is reacting but only 2 mole is required .
Oxygen is in excess.
Answer:
0.015% and 0.012%
Explanation:
using simultaneous equation
Answer:
Acoustic tractor beams use the power of sound to hold particles in mid-air, and unlike magnetic levitation, they can grab most solids or liquids even small insects. For the first time engineers have shown it is possible to stably trap objects larger than the wavelength of sound in an acoustic tractor beam. This discovery could enable the manipulation of drug capsules or micro-surgical implements within the body. The discovery could even lead to levitating humans.
Explanation:
The type of charge an electron carries is B negative