What is the freezing point of a solution of 1.43 g mgcl2 in 100 g of water? kf for water is 1.86°c/m for water.

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

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

As we move from left to right across the periodic table, what is the general trend? a) atomic radii increase. b) electronegavitiy decreases. c) nuclear shielding increases. d) metallic character decreases.