What do elements in the first two columns of the periodic table have in common

Select the correct answer how does the heat content of the reaction change in the process of photosynthesis when a glucose molecule is formed? ca the value of is negative the value of qis positive the value of a remains constant the value of a decreases the value of equals zero e

When an object falls through the air and encounters air resistance its overall speed will be than if it had not encountered air resistance? (one word answer)

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?