A hydrocarbon is a compound that contains mostly carbon and hydrocarbon: Calculate the percent composition (by mass) of the following hydrocarbon: C_6 H_14. Enter the percentages of carbon and hydrogen numerically to four significant figures, separated by commas. A certain metal hydroxide, M(OH)_2, contains 32.8% oxygen by mass. What is the identity of the metal M? Enter the full name of the element.