all the elements in group 18 are Nobel gases or inert gases . all the elements such as neon , helium, argon etc. ,their outermost shell is completely filled . The noble gases have the largest ionization energies, reflecting their chemical inertness
Answer:
0.158 moles KMnO4
Explanation:
According to the Periodic Table,
K = 39.10 g/mol
Mn = 54.94 g/mol
O = 16.00 g/mol
KMnO4 = 39.10 g/mol + 54.94 g/mol + 4(16.00 g/mol) = 158.04 g/mol
25.0 grams KMnO4 1 mole
----------------------------- x -------------------------- = 0.158 moles KMnO4
158.04 grams
C. An atom of helium has its valence electrons in its first energy level, it wouldn't and can't satisfy the Octet rule as it only has 2 electrons, but with 2, it has a full shell, as the first energy level can hold only 2 electrons.
Answer:
Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic.
Explanation:
It is a physical change because only the states as being changes, not the actual bonds in the compound.