Which best describes his claim? it is valid because his experiment had clear variables. it is invalid because his sample size is small. it is invalid because his claim is not based in science. it is valid because he is an expert in his field.

answer; /// the amount of material dissolved in a measure of liquid(concentration) the above statement is (true); /// good luck

answer; protein;

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

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