what is the area of the right triangle formed by halving a square with perimeter 36 along its diagonal? a) 9 b) 18 c) 18+ 9 square root 2 d) 40.5 e) 81
Compare the present Periodic Table with Mendeleevs original Periodic Table in terms of how it is organized, number of elements, what it looks like, ease of understanding, and information given.
Explain what the term "halogen" means and why they have this name, and which halogens exist as a solid, a liquid, and a gas at room temperature.
why were the noble gases considered to be inert gases until the 1960s?