It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms.
These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe. Present observations suggest that the first stars formed from clouds of gas around 150–200 million years after the Big Bang. Heavier atoms such as carbon, oxygen and iron, have since been continuously produced in the hearts of stars and catapulted throughout the universe in spectacular stellar explosions called supernovae.
The answer is A hope this help
Answer:
partly ionic and partly covalent
Answer:
Explanation:
Mass of compound A = 25g
Mass of compound B = 40g
Mass of final mixture = 55g
What happens to the missing mass?
According to the law of conservation of mass, in chemical reaction, matter is transformed from one form to another but cannot be created nor destroyed.
We expect the final mass of the mixture and that of the reacting compounds to be the same but the opposite is the case.
There is a mass loss which typifies most chemical reaction.
The reason for this is that some of the masses must have been lost by the production of gaseous species which are unaccounted for.
The missing mass:
Total mass expected = mass of A + mass of B = 25 + 40 = 65g
Missing mass = expected mass - mass of final mixture = 65 - 55 = 10g
There are 34 g of oxygen in the container.
We can use the<em> Ideal Gas Law</em> to solve this problem.
But 
, so
and
STP is 0 °C and 1 bar, so
