1. You find 25.0 g barium metal in the school chemistry storeroom. If you carefully reacted the barium the barium with 1.00 L of water, determine the concentration of the barium hydroxide solution produced. Assume that the resulting solution is 1.00 L.

0.182M Ba(OH)₂

Explanation:

The reaction of barium metal (Ba) with H₂O is:

Ba + 2H₂O → Ba(OH)₂ + H₂

25g of Ba are:

25g Ba × (1mol / 137.327g) = 0.182 moles of Ba. Based in the reaction, 1 mole of Ba produces 1 mole of Ba(OH)₂. That means you will produce 0.182 moles of Ba(OH)₂. If the whole volume of your solution is 1.00L, the concentration of barium hydroxide is:

0.182 moles of Ba(OH)₂ / 1.00L = 0.182M Ba(OH)₂

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.