please help

7. 9 Hainte: it is an clement or a competal. Fur mictares, ind ale if it is a hemegmeins of henerngeneous mixnire. 4. Iron Metal b. Table Salt. e. Air d. Firanite 4. 10 Points at. A rectangular aquariam has sides with lengts ef 300cm. 20 ocin ard a beight of 15. 0cm. Determine the volume of the aquarim and expeca the anvwer in mL and L b. A javelin thrown by a compctior in a track and ficld estet has a mass of 0.x19kk. Determine the mass of the javelin in terms ef grams and milligrams. 5. 10 Peaints Determine the temperature in C and k for a Fakreaheit reading of 77.0F. 6. Is Points Do the following calculations. Eupress yoar anvwer with the contect number of signiffeat figares and in proper sericntific notation