A student set up an experiment to investigate the law of conservation of mass. The law states that in a chemical reaction, the mass of the products is equal to the mass of the reactants. This is the method that the student followed. Prepare a beaker of lead nitrate solution and label it A. Prepare a beaker of potassium chromate solution and label it B. Measure the mass of both beakers and contents with an accurate and tared balance. Pour the solution from beaker B into beaker A. Immediately measure the mass of both beakers and contents. This is the equation for the reaction which occurs when the solutions are mixed together: Pb(NO3)2(aq) + K2CrO4(aq) ⟶ PbCrO4(s) + 2KNO3(aq) What would the student observe as the reaction takes place?

Asap , 8th grade science 50 points 1) a 2kg bowling ball sits on top of a building that is 40 m tall. what type of energy does it have? potential energy energy of acceleration kinetic energy chemical energy 2) a 2 kg bowling ball sits on top of a building that is 40 meters tall. how much potential energy does it have? 784 j 80 j 784 n 78.4 j 3) a 4 kg bowling ball rolls at a speed of 5 m/s on the roof of a building that is 30 meters tall. what type of energy does the bowling ball have? both potential and kinetic energy kinetic energy potential energy speed 4) a 4 kg bowling ball rolls at a speed of 5 m/s on the roof of a building that is 30 meters tall. what is its kinetic energy? 50 j 10 j 120 j 1,176 j 5) an 8 kg bowling ball rolls at a speed of 10 m/s on the ground. what type of energy does the bowling ball have? kinetic acceleration potential speed 6) an 8 kg bowling ball rolls at a speed of 10 m/s on the ground. what is its kinetic energy? 40 j 80 j 160 j 400 j 7) a 20 kg child is tossed in the air by her parent. what is her kinetic energy when she is 2 meters off the ground traveling at 5 m/s? 200 j 40 j 100 j 250 j 8) a 1,000 kg car has 50,000 j of kinetic energy. what is its speed? 100 m/s 150 m/s 50 m/s 10 m/s 9) a 200 kg boulder has 39,200 j of gravitational potential energy. what height is it at? 50 m 20 m 150 m 200 m 10) a 1 kg model airplane has 12.5 j of kinetic energy and 98 j of gravitational potential energy. what is its speed? 5 m/s 10 m/s 15 m/s 20 m/s

Which of the following might a chemist choose to study? a. glacier movement in alaska b. better ways to recycle plastics c. the effects of hurricanes on turtle populations d. the vibrations in bridges caused by big trucks

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct