50.0 grams of a pure gaseous compound was found to contain 26 grams of oxygen. what is the percentage by weight of oxygen in this compound?
answer in units of g.

If 15 drops of ethanol from a medical dropper weight 0.60g, how many drops does it takes from a dropper to dispense 1.0ml of ethanol? the density of ethanol is 0.80g/ml

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

Need asap question 1 minerals are organic compounds. true false question 2 what vitamin can be found in foods like oranges, grapefruits, and broccoli? a. vitamin a b. vitamin k c.vitamin c d. vitamin d question 3 what are minerals? a. chemical elements that are needed for body processes. b. organic compounds that the body needs in small amounts to function properly. c. small molecules used to build proteins. d. an organic compound that is insoluble in water and includes fats. question 4 how many types of vitamins does the human body need? a. 15 b. 11 c. 13 d. 17 question 5 vitamins are a good source of energy. true false