Answer needed asap.

a student performs a reaction twice. in the second trial, he increases the temperature of the reaction and notes that the reaction happens more quickly. the student concludes that this means the reaction was endothermic. what is wrong with the student's reasoning?

a. higher temperature increases reaction rates for both endothermic and exothermic reactions.

b. an endothermic reaction would not speed up at higher temperatures.

c. temperature does not affect the rate of a reaction.

d. the higher temperature in the second trial actually lowered the activation energy of the reaction.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms