Why compounds are considered as pure substances? no google

Compounds: are pure substances that are made up of more than l type of atom and can be broken down or decomposed into its individual elements by chemical methods, but cannot be separated by physical methods.

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dishwashers don't have rights

explanation:

dishwashers are meant for one thing and one thing only: dishwashing. they belong in the kitchen making sandwiches and cleaning up for the man of their household. if your dishwasher starts acting up just slap it and wait a minute.

- 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