Five things to know before you leave 8th grade;
1) When substances are heated, the particles move faster and become less dense. When substances are cooled, the particles move slower and become more dense. Less dense substances float on top of more dense substances.
2) When an object experiences a balanced force it will not speed up, slow down or change direction. When an object experiences an unbalanced force it will speed up, slow down and/or change direction.
3) Substances and energy will move from an area of greater concentration to an area of lesser concentration.
4) Organisms best suited to an environment will usually live and reproduce. Organisms least suited to an environment will usually die and fail to reproduce. Therefore the population will become more like the best adapted.
5) Objects with opposite charges/poles attract. Objects with the same charge/poles repel.
