The students should be required to pass a standard safety quiz before being allowed to participate in chemical experiments. The standard safety requirements for heating areAlways wear safety glasses. Always point the test tube away from any other person in the lab. Heat the test tube being held at an angle so there is a way for the gases produced to escape safely. Heat the test tube at the top of the solution not the bottom where a gas bubble can cause an explosion. Heat the test tube gently moving the heat away as the solution begins to boil.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

"electrical energy" transforms to "thermal energy".hope my answer has you : )

I’m not sure about this question