Science Exam Study Guide PDF

**Science exam study guide** **1) Properties of protons, neutrons, and electrons.** **Protons: Charge: 1+ Mass: 1 Location: in the nucleus** **Neutrons: Charge: 0 Mass: 1 Location: in the nucleus** **Electrons: Charge: 1- Mass: 1/1840 Location: moving around outside of the nucleus** **2)Use the...

**Science exam study guide** **1) Properties of protons, neutrons, and electrons.** **Protons: Charge: 1+ Mass: 1 Location: in the nucleus** **Neutrons: Charge: 0 Mass: 1 Location: in the nucleus** **Electrons: Charge: 1- Mass: 1/1840 Location: moving around outside of the nucleus** **2)Use the periodic table for locating information about elements: atomic number, atomic mass, element's symbol, and the number of protons & electrons.** **3)Groups and periods in the periodic table.** **Protons and electrons: atomic number** **valence electrons: group number** **1)Define and explain the role of valence electrons.** **They are the electrons of an atom that have the highest energy, they are at the outermost and last energy level, and they participate in chemical bondings.** **2)Describe, compare, and contrast the properties of metals, nonmetals, and metalloids.\ ** **Metals: often shiny; good conductors of electricity and thermal energy; easily pulled into wires and hammered into sheets** **Nonmetals: poor conductors of electricity and thermal energy; most are gases at room temperature; solid form tends to be brittle** **Metalloids: have properties in common with both metals and nonmetals; often used as semiconductors in electronic devices** **3)Short Answers/ Critical Thinking Questions** **What are the key differences between covalent and ionic bonds and compounds?** **Covalent Bonds are formed when two nonmetal atoms share electrons, however, ionic bonds are deformed when a metal atoms transfer electrons to a nonmetal atom. Furthermore, covalent compounds have low melting and boiling points while ionic compounds have high melting and boiling points.** **What are the similarities and differences between electron dot diagrams and electron energy level diagrams?** **Similarities: they both show the number of valence electrons in an element** **Differences: the electron energy level diagram demonstrates the amount of electrons in an element by energy levels around the atom while an electron dot diagram represents valence electrons as dots around the element's symbol.** **Topic 2** **1) Vocabulary- mixture, colloid, suspension, solution.** **A mixture is made of two or more substances that are together in the same place, but their atoms are not chemically combined.** **Colloids have tiny, tiny pieces that are mixed together but don\'t settle down even if you leave them alone.** **A suspension is a mixture with particles that can be seen and easily separated by settling or filtration**. **1) Vocabulary -reactant, product, exothermic reaction, endothermic reaction** **A reactant is a substance that undergoes a chemical change in a reaction.** **A product is a substance that is formed as a result of a chemical reaction.** **Chemical reactions that RELEASE thermal energy (heat and light) are called Exothermic reactions.** **Chemical reactions that ABSORB thermal energy (heat and light) are called Endothermic Reactions.** **2) Identify Physical or Chemical Changes** **A physical change changes the shape of an object, but does not make the material into another substance, A chemical change forms new substances** **3)Short Answers/ Critical Thinking Questions** - **Exothermic: Chemical reactions that RELEASE thermal energy (heat and light). The energy released as the products form is greater than the energy required to break the bonds of the reactants. Example: Light is released from a light bulb** **1) Vocabulary - Law of conservation of mass** **The idea that matter is never created or destroyed in any chemical or physical change is called the law of conservation of mass** **2) Recognize the types of chemical reactions.** **Word equations use words, skeleton Equation uses chemical symbols and formulas for reactants and products, Ball Equations uses diagrams of molecules and atoms for reactants and products** **3) Identify reactants and products in chemical equations.** **Reactants are on the left side and products are on the right** **4) Short Answers/ Critical Thinking Question(s)** ** Explain how the mass of reactants and products demonstrate the law of conservation.** **The law of conservation of mass states the total mass of the reactants must equal the total mass of the products in a chemical reaction because mass is neither created nor destroyed it\'s just rearranged.** **Topic 3** **1) Vocabulary - reference point, motion, net force** **A reference point is an object used for comparison to determine whether something is in motion.** **Motion is the change of an object overtime** **Net Force is the combination of all of the forces acting on an object.** **2) Applied forces - balanced/ unbalanced and net force** **Google form,** **3) Short Answers/ Critical Thinking Questions** **In terms of reference points, explain why is motion relative. Provide examples of an object in motion and not in motion.** **Because motion is determined by a reference point that can change, motion is relative.** **Example: in a moving car, a dog is in motion relative to a tree** **Example: in a moving car, a dog is not in motion relative to car** **How are contact forces different from non-contact forces? Give examples.** **Contact forces occur with physical contact, noncontact forces act on the objects without touching.** **Example of contact: Move a table across the floor.** **Example of noncontact: Free fall of a ball** **1) Vocabulary - speed, velocity, and acceleration** **The speed of an object is the distance it travels over a unit of time. Formula: distance/time** **Velocity is the speed at which an object travels in a given direction.** **Acceleration is the rate at which velocity changes** **2) Short Answers/ Critical Thinking Questions** **In terms of speed, direction, and velocity give all the similarities and differences between two objects in motion.** **They are going the same speed, they have opposite directions, and they don\'t have the same velocity.** **1) Vocabulary - Newton's Laws of Motion- Explain and Apply the Laws** **First law: an object at rest will remain at rest or an object moving at a constant velocity will continue moving at a constant velocity unless acted upon by a non-zero net force** **Second law: an object's acceleration depends on its mass and on the net force acting on it** **Third law: every action has an equal and opposite reaction** **2) Short Answers/ Critical Thinking Questions** **Analyze the difference between balanced forces and action-reaction forces and apply your understanding to real-life examples.** **Balanced forces act on the same objects while action-reaction forces act on different objects**