8.1 test

Each particle that moves around the center is called a(n)________. nucleus neutron proton electron isotope

electron

A positively charged particle in an atom is a(n)________. nucleus electron isotope proton core neutron cloud

proton

When you were young, you may have had your own theory about why plants are green. Then, as you learned more, you kept ideas that were correct, but replaced ideas that were incorrect. Atomic theory also changed as scientists improved their understanding. Which incorrect idea in Bohr's understanding of the atom was replaced by later theories? Atoms cannot be divided. An atom is mostly empty space. In an atom, electrons orbit the nucleus like planets orbit the sun. An atom includes electrons embedded in a sphere of positive

In an atom, electrons orbit the nucleus like planets orbit the sun.

Rutherford's gold foil experiment showed several new things about the structure of the atom. Which results support the claim that the atom has a dense, positively charged core? Choose the two statements that apply. Some positive particles deflected at sharp angles. Most of the positive particles passed straight through the foil. Some negative particles deflected at sharp angles. Some positive particles bounced back in the direction they came

Some positive particles deflected at sharp angles. Some positive particles bounced back in the direction they came

New theories usually don't start "from scratch." For example, the modern model of the atom is the result of new information added to the cloud model. What is the main difference between the cloud model of the atom and the modern model? Only the modern model includes protons. The cloud model does not include neutrons. Electrons move in specific orbits in the modern model. Electrons exist in a cloud around the nucleus in the cloud model.

The cloud model does not include neutrons.

A particle in an atom with no charge is a(n)________. nucleus electron isotope proton core neutron cloud

neutron

Protons and neutrons form a dense center called the______. nucleus electron isotope proton core neutron cloud

nucleus