Help please Students were asked to compare Sodium, Magnesium, Potassium, and Calcium,
Which statement is true
A. Na and Mg have 3 valence electrons
B. Na and K are highly reactive C. K and Ca are in the same group
D. Mg and Ca have two energy levels.

Subduction zones occur on earth where dense oceanic crust dives under more buoyant continental crust. these boundaries are characterized by a deep ocean trench next to a high continental mountain range, large numbers of earthquakes and volcanoes. all of this is further evidence for the a) big bang theory b) origin of the species eliminate c theory of plate tectonics d theory of natural selection 4 sedimentary rocks found high in the himalayen mountain

Pbco3 –> pbo+ co2. how many liters of carbon dioxide gas is produced from the decomposition of 32 grams of lead (ll) carbonate?

In a spacecraft, the following reaction occurs: co2(g) + 2lioh(s) -> lico3(s) + h2o(i) (i attached picture of equation) how many liters of carbon dioxide will 4 moles of lithium hydroxide (lioh) absorb? (one mole of any gads occupies 22.4 l under certain conditions of temperature and pressure. assume those conditions for this equation.) 45l 6.0l 3.0l 34l