With your class, look up the element names for each symbol in the word "BOOK" and list the element names.

Explanation:

The word BOOK; is made up of 4 letters and each actually represents the symbol of an element.

An element is a distinct substance that cannot be split-up into simpler substances.

  B    -   Boron

  O    - Oxygen

  O   - Oxygen

  K   - Potassium

We can see that the word BOOK shows us elements boron, oxygen, oxygen and potassium.

- 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