Third quarter (or last quarter)
Answer:
One distinguishing feature between physical and chemical changes is that a physical change can be reverse or turn back to its original form, but chemical change cannot be return to its form because the material change.
Explanation:
Answer:
the stoichiometric coefficient for cobalt is 3
Explanation:
the unbalanced reaction would be
Co(NO₃)₂+ Al → Al(NO₃)₃ + Co
One way to solve is to build a system of linear equations for each element (or group as NO₃) , knowing that the number of atoms of each element is conserved.
For smaller reactions a quick way to solve it can be:
- First the Co as product and as reactant needs to have the same stoichiometric coefficient
- Then the Al as product and as reactant needs to have the same stoichiometric coefficient
- After that we look at the nitrates . There are 2 as reactants and 3 as products . Since the common multiple is 6 then multiply the reactant by 3 and the product by 2.
Finally the balanced equation will be
3 Co(NO₃)₂+ 2 Al → 2 Al(NO₃)₃ + 3 Co
then the stoichiometric coefficient for cobalt is 3
A covalent bond describes two atoms (most likely nonmetals) that share their valence electrons to satisfy the octet rule. Carbon and oxygen are both nonmetals, and they would share electrons with each other through a bond that is not polar enough to be considered ionic. The answer should be B
