Seconds Left: A stable carbon atom has the following parts: – 6 protons – 6 neutrons – 6 electrons Describe the location of each of these parts in a carbon atom.

Protons and neutrons are found in the nucleus of the atom, at the very center. Electrons are found in an electron cloud that surrounds the nucleus.

This screen will disappear in 3 minutes. Seconds Remaining. Describe the three kinds of particles found in atoms. Where are they located & what are their charges?

Protons – in the nucleus, positive charge Neutrons – in the nucleus, no charge Electrons – outside the nucleus, negative charge

Seconds left: An electrically neutral atom undergoes a change to become negatively charged. The atom's atomic mass decreases. A student explains that the atom most likely lost a neutron. – Describe one strength and one weakness of the student's explanation.

One strength of the explanation is that an atom's mass consists mostly of the mass of its protons and neutrons. Electrons have very little mass. So, the atom must have lost either a proton or neutron. One weakness, however, is that neutrons have no charge. So, removing the neutron should not affect the atom's charge. It is more likely that a proton was removed.

You have Seconds left. Draw the Diagram –Identify the four parts of the atom that are pointed out by arrows in the diagram above. –Describe the electrical charges of the structures that are labeled 1, 2, and 3 in the diagram.

Number 1 is the electron, 2 is the proton, 3 is the neutron, and 4 is the nucleus. The electron is negative. The proton is positive. The neutron is neutral.

Time left:Seconds Define these terms: Atom Isotope Ion

ATOM – the smallest part of matter that has the properties of the matter ISOTOPE – different forms of the same atom; they have the same numbers of protons, but different numbers of neutrons ION – an atom that has lost or gained electrons

Seconds Left: An atom consists of 7 neutrons, 7 electrons, and a number of protons. The atom has a charge of -1. What is its mass number ?

The atom has a mass number of 13 To find the mass number we have to know the # of protons & the # of neutrons. –We know there are 7 neutrons; ??? protons An atom with a charge of -1 has gained an electron (added a – charge) Atoms begin w/ = numbers of protons & electrons, so the atom began with 6 electrons & 6 protons. 6 protons + 7 neutrons = a mass # of 13

SecondsRemaining: What are the biggest parts of an atom ?

Protons & Neutrons

Seconds Left: A stable helium atom contains 2 protons, 2 neutrons, and 2 electrons. – Draw and label a diagram of a stable helium atom. Be sure to include the protons, neutrons, electrons, and nucleus of the atom in your diagram.

Helium Atom