Answer:
Dissolving sugar in water, burning paper, and melting gold are all chemical changes
Explanation:
The action cannot be reversed, or undone. Therefore it is a chemical change.
Boiling water is a physical change.
Answer:
Calcium can be ignited and will when burning react with both oxygen and nitrogen forming calcium oxide, CaO, and calcium nitride, Ca3N2.
Out of the three you gave ecosystem is what I would call the most broad. An ecosystem includes living AND non-living things in an area
Community is all the LIVING things in an area (plants are included and I think bacteria is too, but I'm not sure)
Population is pretty narrow it just looks at specific species in one area. Population of mosquitoes doesn't include butterflies, if only looks at mosquitoes
Hope this helped!
Answer:
To calculate the molar mass of a compound with multiple atoms, sum all the atomic mass of the constituent atoms molar mass can also be calculated by multiplying the atomic mass in amu by the molar mass constant (1 g/mol).
