PLEASE HELP I got this wrong on an exam but got it wrong and i don’t know why! Which of the following four measurements has the smallest uncertainty percentage?

A 9,99 cm +/- 0,005 cm
B 4,44 cm +/- 0,005 cm
C 1,11 cm +/- 0,005 cm
D 5,55 cm +/- 0,005 cm

- 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

answer seismograph;