What mass of copper sulphate dissolves in 200g of water at 70 °C

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

Ineed a picture or something 

In order to improve results, many different steps can be taken into account. 1) using more precise scales and thermometers is always something that should be considered as being precise means that you are more exact with your answer.2) increasing the sample size should also be considered, if you have a bigger sample size you are able to determine if your results are accurate as well as if there are any variables that should be taken into account plus it assists in the statistical analysis and produces overall better data3) using better handwriting is also a plus, along with organizing the data properly so that others are also able to read the results and even redo the experiment in the future if it is needed.

The atoms (or molecules) within the substance move slower, as temperature decreases.