After James Chadwick discovered the neutron, atomic theory expanded to include isotopes. Isotopes have many practical uses. For example, scientists use the relative amount of carbon-12 to carbon-14 in ancient bones to determine how old they are.
Isotope
Carbon-12 Carbon-14
Protons
6
Neutrons
6
Atomic mass
14 amu
James Chadwick, like Ernest Rutherford, had to infer that neutrons were present in atoms. He made inferences based on observations of the
behavior of atoms during experimental tests. Using evidence from Rutherford's gold foil experiment, defend the following claim: Scientific
knowledge is based on observation and inference.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

it's 3.2 on edge, i just took the test.