12/17/2023 0 Comments Element cl protons neutrons electronsMatter is any substance that occupies space and has mass. Īt its most fundamental level, life is made up of matter. These questions address the following standards: The Science Practice Challenge Questions contain additional test questions for this section that will help you prepare for the AP exam. Growth, reproduction and maintenance of living systems require free energy and matter.Ģ.A.1 All living systems require constant input of free energy.Ĥ.1 The student can justify the selection of the kind of data needed to answer a particular scientific question.Ħ.2 The student can construct explanations of phenomena based on evidence produced through scientific practices.Ħ.4 The student can make claims and predictions about natural phenomena based on scientific theories and models.Ģ.8 The student is able to justify the selection of data regarding the types of molecules that an animal, plant, or bacterium will take up as necessary building blocks and excrete as waste products. A Learning Objective merges required content with one or more of the seven Science Practices.īiological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis. The Learning Objectives listed in the Curriculum Framework provide a transparent foundation for the AP ® Biology course, an inquiry-based laboratory experience, instructional activities, and AP ® Exam questions. The information presented and examples highlighted in this section support concepts and Learning Objectives outlined in Big Idea 2 of the AP ® Biology Curriculum Framework. Isotopes are different forms of an element that have different numbers of neutrons while retaining the same number of protons many isotopes, such as carbon-14, are radioactive. Electrons can be transferred, shared, or cause charge disparities between atoms to create bonds, including ionic, covalent, and hydrogen bonds, as well as van der Waals interactions. Atoms, which consist of protons, neutrons, and electrons, are the smallest units of matter that retain all their characteristics and are most stable when their outermost or valence electron shells contain the maximum number of electrons. The 92 naturally occurring elements have unique properties, and various combinations of them create molecules, which combine to form organelles, cells, tissues, organ system, and organisms. Matter is anything that occupies space and mass. Living systems obey the laws of chemistry and physics. What are the differences among ionic bonds, covalent bonds, polar covalent bonds, and hydrogen bonds?.How does atomic structure determine the properties of elements, molecules, and matter?.It can be mathematically calculated using the formula below.In this section, you will explore the following questions: The relative atomic mass of an element takes into account all its naturally occurring isotopes when compared to 1/12th the mass of carbon 12. 92% of all lithium in the known universe is Lithium 7 - having 3 protons and 4 neutrons. The abundance of an isotopes is the percentage of that isotope in existence. This is because Lithium has isotopes that range from having 0 neutrons up to 13 but they all have different abundances. It has a mass number of 6.941 which in most periodic tables is rounded up to 7. Looking at another example Lithium has many isotopes. They are chemically the same, the only difference is Chlorine 35 contains 18 neutrons and Chlorine 37 contains 20 neutrons, both still have the same number of protons 17 and 17 electrons as you can see in the table. The key difference is the difference in mass number, this is caused by different number of protons. They have the same reactivity due to the number of electrons and also the same atomic number. As they have the same number of protons they will have the same atomic number and the same number of electrons. This is because in nature there there are two types of Chlorine atoms and they have different numbers of neutrons but the same number of protons. For example with Chlorine, the Atomic Mass is given as 35.5, this is because there are two forms of Chlorine as an element. Sometimes the Atomic Mass, unlike the Atomic number, is usually given as decimals.
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