Workers who build railway tracks often use a process called thermite welding to connect pieces of track. Thermite is a mixture of aluminum metal (Al) and ferric oxide (Fe2O3). A worker places thermite between two pieces of track and then burns it to form aluminum oxide (Al2O3) and iron (Fe). As the reaction happens, the air around the mixture becomes so hot that the two pieces of track fuse together. Is this chemical exothermic or endothermic?

Which of the following are sources of revenue for media companies? a. direct sales to producers b. advertising and subscriptions c. online purchase d. capital investments

Use the periodic table to find the molar mass of each element. molar mass h = g/mol molar mass s = g/mol molar mass o = g/mol

Movement that is like a t a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. transfers energy from one location to another a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave