HESI A2 Chemistry Practice Test 2023 What makes an atom's physical structure? - Correct Answer A nucleus and orbits(sometimes known as electron clouds) What composes the center of the atom? - Correct Answer Protons and neutrons What spins in the orbits of an atom? - Correct Answer Electrons What are the energy levels of the atom called? - Correct Answer Shells or orbits What is the term used to define an atom that is electrically charged? - Correct Answer Ionic state.What is a cation? - Correct Answer An atom with a positive charge What is anion? - Correct Answer An atom with a negative charge What is the structure of the periodic table? - Correct Answer A series of rows called periods, and columns called groups.What can be predicted by the group an element occupies? - Correct Answer Charge and the numbers of electrons in its outer shell.What is the name and properties of group VIII of the periodic table? - Correct Answer Noble gases.They tend to remain neutral in most situations, because their outer orbits are complete.What is the atomic number? - Correct Answer The number of protons in the nucleus, defines an atom of a particular element.What is the atomic mass? - Correct Answer The average mass of an element's isotopes.What are isotopes? - Correct Answer Different kinds of the same atom that vary in weight.What is a compound? - Correct Answer The combination of different elements.What do chemical reactions resemble? - Correct Answer A cooking recipe.What are the reactants in a chemical reaction? - Correct Answer The ingredients of a chemical reaction.What is the term given to the results of a chemical reaction? - Correct Answer The products. 1 / 2
Why must a chemical equation be balanced at the end of a reaction? - Correct Answer Because the law of conservation of mass indicates that mass cannot be created nor destroyed in a chemical reaction.What are equilibrium reactions? - Correct Answer Chemical reactions that stop before all the reactants are used to make the products.What causes equilibrium? - Correct Answer The state in which reactants are forming products at the same rate that products are forming reactants.What are the four basic ways to increase the reaction rate? - Correct Answer Increase temperature Increase the surface area of the reactants Add a catalyst Increase the concentration of the reactants.What does increasing temperature cause in a chemical reaction? - Correct Answer The particles have greater kinetic energy, increasing the speed at which they move around, and the chance of collision between particles.How does increasing the surface area of the particles in a reaction speed chemical reactions? - Correct Answer Gives the Particles more opportunities to come in contact with each other.What is a catalyst? - Correct Answer An agent that accelerates a chemical reaction by reducing the activation energy or the amount of energy necessary for a reaction to occur.What is the effect of increasing the concentration of reactants in a chemical reaction? - Correct Answer More chance collisions occur between the reactants, producing more products.What is a solution? - Correct Answer A homogeneous mixture of two or more substances.What is a solute? - Correct Answer The part of a solution being dissolved.What is a solvent? - Correct Answer The part of a solution the solute is being dissolved in.What are compounds? - Correct Answer Mixtures of different elements to create a single matter.What are alloys? - Correct Answer Solid solutions of metals to make a new one. e.g.bronze ( a mixture between copper and tin)
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