This week in science we started our chemistry unit. We learned that the smallest unit of matter is an atom. Atoms make up molecules and matter. We also learned that there are different things that can affect the movement of particles. The one we discussed in class is the energy changes in the room. If the room is experiencing cooling the energy decreases, slowing the particles, and changing the substance into a solid. If the room is experiencing heating, the energy increases and the particles speed up, changing the substance into a gas. An atom is made up of three things electrons, neutrons, and protons. An electron exists out side of the nucleus and are negatively charged. A neutron exists inside the nucleus and is neutrally charged. A proton exists inside the nucleus and is positively charged. In an atom there are an equal amount of protons and electrons. We also learned that the atomic number tells the number of electrons and protons an element has. If the number of protons changes then the element changes. We also learned that the atomic mass is two times the amount of the atomic number. We also learned two terms for having more electrons and protons than needed. One is an ion which is having more or less electrons than needed. The other is an isotope which is having more or less neutrons than needed. The carbon 14 element is carbon with two additional neutrons.