Answer: Mixture
Explanation:
Element is a pure substance which is composed of atoms of similar elements.
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. Example: Air which conatins a mixture of 
, 
, 
and 
Answer:
B
Explanation:
A chemical reaction equation is balanced if the number of atoms of each element on the right hand side of the reaction equation is the same as the number of atoms of the same element on the left hand side of the reaction equation.
By inspection, the chemical reaction written in the question is a balanced chemical reaction equation.
However, the statement in option B that more molecules of N2 are needed to produce NH3 than molecules of H2 is a false statement since only one mole of N2 and three moles of H2 are required to produce NH3 according to the reaction equation as written in the question.
Well that depends on the central atom. Remember each bond indicates another electron that is being shared with the central atom.
So CO4, carbon would be your central atom, with the 4 oxygen around it. There would be no double bonds because carbon only requires the 4 electrons provided by the oxygens, because of its location on the periodic table.
Nitrogen on the other hand is different. It's found in group 5 (5V) and has 5 valence electrons on its outer shell. So NO4 would have a central Nitrogen atom, with 3 oxygens providing a single bond, and one oxygen providing a double bond, because Nitrogen needs 5 electrons!
We learned it like this, the atom brought x amount of electrons to the party, x representing the valence electrons, and must leave with x electrons. It's silly but it works!
I hope I was able to help and clarify a few things up!
Answer:
0.64 g O₂
Explanation:
I am assuming you meant 0.02 moles of O₂. In that case, convert moles to mass via stoichiometry:
0.02 mol O₂ x 32 g O₂/1 mol O₂ = 0.64 g O₂
Explanation:
during the daytime just complete your lessons of biology, during the midday timechemistry or study it in evening, at night physics and just try to complete those chapters that are difficult for you and the easier one you could do at last simple and take Sunday as a day for revision...
Give 2hrs, 1hr each chapter...
