Answer:
Bottom left corner of the periodic table
Explanation:
The elements toward the bottom left corner of the periodic table are the metals that are the most active in the sense of being the most reactive. Lithium, sodium, and potassium all react with water, for example.
Explanation:
Composition of Stainless Steel
Steel is an alloy of iron and carbon. Stainless steels are steels containing at least 10.5% chromium, less than 1.2% carbon and other alloying elements
I think it may be “past climate of Earth seen in glaciers”/ I learned about this and that one doesn’t really ring a bell, plus it doesn’t make sense to me. I four sure know it’s not the fitting like a puzzle one. Sorry if I get this wrong.
Answer:

Explanation:
S is in 3d period, so it has 3 levels
1 level has 2 electrons, 2d level 8 electrons, 3d level 6 electrons

Answer:
The answer to your question is 58.7 g of Ca(OH)₂
Explanation:
Data
mass of Ca(OH)₂ = ?
mass of HNO₃ = 100 g
Process
1.- Write the balanced chemical reaction
Ca(OH)₂ + 2HNO₃ ⇒ Ca(NO₃)₂ + 2H₂O
2.- Calculate the molar mass of the reactants
Ca(OH)₂ = 40 + 32 + 2 = 74 g
HNO₃ = 1 + 14 + 48 = 63 g
3.- Use proportions to calculate the mass of Ca(OH)₂
74 g of Ca(OH)₂ ----------------- 2(63) g of HNO₃
x ----------------- 100 g of HNO₃
x = (100 x 74) / 2(63)
x = 7400 / 126
x = 58.7 g