A student is using one and the same conical flask to make up several solutions of 1 M HCl solution in the lab one day. It is a very hot day and the student measures the temperature in the lab and find it fluctuates between 30C and 36C. The student is not measuring the temperature between each solution. Would you describe the error introduced by this temperature change as a systematic error? True or false

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. 

And a) oxygen i believe