Http://www.chem4kids.com/files/elem_pertable.html this should help.
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Ex: cutting a paper, gaining weight, cutting hair
Answer:
The answer is hardness and brittleness. The ion discharging procedure and taking after impact on reservoir water quality file, for example, hardness, pH, conductivity, has been dissected. Comes about uncovered that the most discharge quality of various materials was touching base at the 30s after startup.
Explanation:
A isotope is atoms of the same element with different amount of neutrons to change the mass. They can become more stable by sharing or giving away electrons to have a stable electron shell
All chemical reaction between substances results into a chemical change. When two substances just like HCL and NaOH reacts with each other, NaCl means Sodium Chloride salt is formed.
The phenomenon like change in color, change in temperature, release of gas etc when happens ,then it means chemical change has been occurred. e.g
HCl +NaOH ----> NaCl +H2O.
