How may a substance be tested to determine whether or not it is an element

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

Quickly! brainliest if two people answer! 1. the blood has red blood cells, white blood cells and platelets. red blood cells carry oxygen to other cells in the body. cells need oxygen to live. white blood cells destroy certain germs. they protect our bodies from disease. which question is answered in this paragraph? (a) what is the role of blood vessels? (b) what type of cells are attached to bones? (c) what type of blood cell to clot your blood? (d) what are the different types of blood cells? 2. which sentence from the section "stem cells" best explains the role of stem cells? (a) when one kind of cell stops working, stem cells can . (b) they can turn into that cell and take its place. (c) scientists are studying new ways to use stem cells. (d) these cells can people heal faster. 3. read the selection from the section "nerve cells." nerve cells send messages to the rest of our bodies. these messages move between the brain, spinal cord and various organs. nerve cells are also called neurons. fill in the blank. a "neuron" is a (a) cell that moves information from the brain to other parts of the body (b) stem cell that has both an axon and a dendrite (c) cell that controls the fingers of a body (d) cell that makes up the spinal cord 4. some muscles in our body move without us telling them to. these are called involuntary muscles. some examples are the cardiac muscle cells inside the heart. these cells the heart relax and fill with blood. what is the best definition of "involuntary" based on the context clues? (a) something that happens on its own (b) trying hard to do something (c) something moving back and forth (d) easily moved

Match each term to its description. match term definition excess reactant a) reactant that can produce a lesser amount of the product limiting reactant b) amount of product predicted to be produced by the given reactants theoretical yield c) reactant that can produce more of the product