If 7.50 g of the unknown compound contained 0.250 mol of c and 0.500 mol of h, how many moles of oxygen, o, were in the sample?

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

The is a particle with one unit of positive charge a. proton b. positron c. electron d. nucleus awnser quick it is a important science test!

Draw the structure for 5-isopropyl-2-methyl-3-nonene