Answer Choice: C
Explanation: Mendeleev is best known for publishing the first periodic table of elements in 1869, revolutionizing the world's understanding of physics and chemistry; and, really almost every aspect of science.
Nonmetals which are located in the second row form pi bonds
more easily than the elements situated in the third row and below. Actually there
are no compounds or molecules known that forms covalent bonds to the noble gas
Ne and Ar. Hence the other second row element which is Carbon, is the element that
forms
pi bonds most readily.
Answer:
<span>C</span>
Answer:
Dark matter is nonluminous material that is postulated to exist in space and that could any of Several form including weakly interacting particles.
Explanation:
dark matter is basically composed of particles that do not absorb, reflect or emit light, so they can't be detected by observing electromagnetic radiation.
Answer : The mass of reactant
remain would be, 0.20 grams.
Solution : Given,
Moles of
= 0.40 mol
Moles of
= 0.15 mol
Molar mass of
= 2 g/mole
First we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,

From the balanced reaction we conclude that
As, 1 mole of
react with 2 mole of 
So, 0.15 moles of
react with
moles of 
From this we conclude that,
is an excess reagent because the given moles are greater than the required moles and
is a limiting reagent and it limits the formation of product.
The moles of reactant
remain = 0.40 - 0.30 = 0.10 mole
Now we have to calculate the mass of reactant
remain.


Therefore, the mass of reactant
remain would be, 0.20 grams.
Answer: 3.62 that's your answer! Please mark me as brainlyest!?
Explanation: