List advantages and disadvantages of using scientific models.

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

To calculate percent by mass, use the equation below: calculate the percent by mass of each element. %n = % %h = % %o = %