Dilute hydrochloric acid used in the school laboratories usually has a concentration of 2.Omol dm-3. Calculate
the mass of hydrogen chloride that found in 250 cm3 of
the hydrochloric acid?[ Ar H.1; C1,35.5]​

that tool would be a compass

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.

diaria maybe go see a doctor about that