Pure- table salt
Impure- vegetable oil
Answer:
1. the group number of sodium is 1 and it is a metal
2. the group number of helium is 18 and it is a nonmetal
3. the group number of iodine is 17 and it is a nonmetal
4.the group number of calcium is 2 and it is a metal
5. lithium has similar properties to potassium
6. calcium has similar properties to magnesium
7. neon has similar properties to xenon
8. Iodine has similar properties to chlorine
Answer:
Zn+2HCl→ZnCl2+H2
Explanation:
Hydrogen gas is prepared in the laboratory by reacting dilute HCl with granulated zinc.
Nuclear fusion in the sun involves hydrogen (H) atoms
combining to form helium (He). A student claims that since the atmosphere
contains hydrogen, any fusion reaction on Earth would result in an uncontrolled
chain reaction. What is wrong in the student’s reasoning is that the uncontrolled
chain reactions can only happen during nuclear fission.
If the energy level of a certain element is filled based on the maximum number of allowable electrons per level, then it is no longer reactive. With this, half-filled energy level means that the element may retain those electrons and attract electrons from other elements or it may give off its electrons.
