Asingle covalent bond involves two atoms sharing one pair of electrons. true false

The given statement is true.

Explanation:

When there is sharing of an electron between two atoms then the bond formed between them is covalent bond.

For example, atomic number of calcium is 20 and its electronic configuration is 2, 8, 8, 2. Whereas atomic number of fluorine is 9 and its electronic configuration is 2, 7. So, in order to attain stability calcium will donate its extra electron to fluorine atom and thus readily combines with two fluorine atoms.

Thus, we can conclude that the statement a single covalent bond involves two atoms sharing one pair of electrons, is true.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them