What do they look like? Tree swallows are small birds (about 14 cm long) with long wings and small legs and feet. They are irridescent greenish-blue on their head, shoulders and back, and white their chin, breast and belly. Tree swallows have a short black beak and dark brownish feet.
Ernest Rutherford concluded that an atom contains a very small, dense center, called a nucleus, with a positive charge as a result of his gold foil experiment.
The model states that the atom consists of a dense positive center called the nucleus and is orbited by negatively charged electrons. The nuclear model of the atom was first proposed by New Zealand scientist Ernest Rutherford while working in England under J. J. Thomson.he nuclear model of the atom describes the atom as consisting of a positively charge dense nucleus made up of protons and neutrons. Negatively charged electrons orbit the nucleus at a great distance from the nuclues.