The mixing of which pair of reactants will result in a precipitation reaction? a. ba(no3)2(aq) + na2co3(aq) b. nh4br(aq) + nh4i(aq) c. k2so4(aq) + cu(no3)2(aq) d. naclo4(aq) + (nh4)2s(aq)

A. Ba(NO₃)₂(aq) + Na₂CO₃(aq)

Explanation:

Ba(NO₃)₂(aq) + Na₂CO₃(aq) → BaCO₃(s) + NaNO₃(aq)

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.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them