Answer:
Ways to Make the World a Better Place
Volunteer your time at local schools. Whether you have a school-age child or not, children are the future of this world. ...
Recognize the humanity of other people, and respect their dignity. ...
Use less paper. ...
Drive less. ...
Conserve water. ...
Donate to clean water charities. ...
Be generous.
Yes, the data from mass spectrometry has helped modern scientists to make modifications to Dalton's model.
Dalton's model consisted of a single atom and that basically the atom is the smallest object. At the time, no discovered what are inside of atoms.
Atoms are made up of small particles, protons, neutrons and electrons. A mass spectrometer is an instrument that is able to see what is inside an atom. With this item, scientists have proved that atoms are not the smallest in the world cause the objects in them are smaller.
Density is mass per volume 
With data:
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Hope this helps.