Part A: On a hot day, a concrete sidewalk feels hotter than the water in a small swimming pool. And a sandy beach feels hotter than the lake or ocean. What do these observations tell you about temperature changes when different materials are heated? Part B: Plan a controlled experiment to investigate how much the temperatures of cold sand and cold water change when hot water is added to them. Assume you have access to water, sand, containers, ice, a heat source, a scale, and thermometers. Summarize your experiment in a few sentences.

Part C: For your experiment in part B, which factors would you keep constant?

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.