N = 4 to n = 3 is the right answer, so it' none of the above
I think it is not possible to make cd without plastic . because except plastic no other material is so durable for making cd.
Answer:
True
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Answer:
Both are pure substances and a compound
Answer:
The distance from Earth to the sun is called an astronomical unit, or AU, which is used to measure distances throughout the solar system.