50 pts don't dare to answer wrong or just write irrelevant. answer must be with explanation. would mark brainliest.

Answer/Explanation:

Part 1 and 3: Test tube 4. The hot water and Acid added to the substance makes it much more reactive, which is the reason why the new substance is bubbling. Hot water allows the particles in a chemical reaction have enough force and more chances to go through actual reaction process. This also caused it to create the most bubbles.

Part 2 and 4: Test tube 1 had the least amount of chemical reactivity. Cold water slows down the amount of times a particle in the substance hits another. This reduces the chance of it reacting and the strength of it's reaction. Test tube 1 was also missing the citric acid. Since acids have low pH it is very reactive with other particles with substances that contain less than 8 valence electrons. Without the acid it doesn't have ad much urge to react with. The lower the pH the better reactivity.

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.

the awnser is group 12