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Praxis Physics Basic Principles

Subjects : praxis, science
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. The smallest unit of matter that has the characteristics of an element; consists of three main types of subatomic particles: protons neutrons and electrons.






2. Atoms that have an unstable nucleus that has excess energy and the potential to make radiation particles within the nucleus or undergo radioactive decay which can result in the emission of gamma rays. May occur naturally or artificially produced.






3. Capable of interacting with a surrounding environment and can exchange heat - work (energy) and matter outside their system boundaries






4. The time it takes for half of the radioactive nuclei in a sample to undergo radioactive decay.






5. This refers to objects that have the same temperature b/c heat is transferred between them to reach equilibrium






6. Can be Beta - Minus or Beta Plus. Beta - Minus: contain an energetic electron Beta - plus: emitted by positrons and can result in gamma photons. Beta particles can be stopped by thin metal.






7. Energy transferred to a body by a means other than work. (through the process of heat)






8. A change that results in a different substance. They may release or consume energy.






9. The measure of the ratio of a substance's density compared to the density of water.






10. Conservation of Energy (energy can only be transferred - not created or destroyed)






11. Refers to everything outside a thermodynamic system.






12. A change that does not result in different substances; when an object changes form but not compostion.






13. Homogeneous mixtures composed of two or more substances that have become one






14. Measurement of the amount of cubic space occupied.






15. A Machine that converts thermal energy to mechanical energy that can be used to do work






16. Positive; larger than Beta. Because of their large mass they can be easily stopped (even with a sheet of paper.) Can cause severe damage if ingested.






17. Measure of the amount of mass per unit volume.






18. A System that cannot exchange heat - work - or matter with its surroundings. Total Energy & Mass stay constant w/in system






19. The quantity of energy transferred by one system to another due to changes in a system that is the result of external forces; also can be described as the amount of energy that must be transferred to overcome a force.






20. Total Kinetic Energy and Potential Energy in a system






21. When energy is emitted by one body and absorbed by another






22. Joining of two nuclei; occurs under extreme temperatures and pressure. Fusion occurs naturally in stars (responsible for the release of great energy).






23. Branch of Physics that studies the conversion of energy into work and heat. Concerned w/ variables such as temperature - volume - and pressure






24. Substances that have mass and occupy space






25. Splitting of a large nucleus into smaller pieces






26. Solid - Liquid - Gas






27. A misguided belief that a system can continuously produce more energy than it consumes.






28. AKA Mass Number. The total number of protons and Neutrons in the nucleus of an atoms. Referred to as 'A.'






29. 1st (K Shell) = 2 electrons - 2nd (L Shell) = 8 electrons - 3rd (M Shell) = 18 electrons - 4th (N Shell) = 32 electrons






30. Measurement of Work






31. Refers to the fact that the total amount of energy in a closed system is constant






32. Isotopes that have unstable nuclei and can undergo spontaneous nuclear reactions which results in particle or radiation being emitted.






33. Two or more atoms held together by covalent bonds






34. Ratio of the average mass per atom of a sample (which can include various isotopes) to 1/12 of the mass of an atom of carbon -12.






35. Attributes such as appearance - color - mass - and volume.






36. Rate at which work is performed






37. Substances that consist of only one type of atom






38. Type of High energy electromagnetic radiation consisting of photons. It rids the decaying nucleus of excess energy after it has emitted either alpha or beta radiation. They can cause serious damage to living tissue. It takes thick lead to stop them.






39. Contain two or more substances that are combined but have not reacted chemically. They can be separated using physical methods






40. Refers to the particles that are emitted from nuclei as a result of nuclear instability






41. Occurs when an unstable atomic nucleus spontaneously loses energy by emitting ionizing particles & radiation. It is a form of energy transfer. Before Decay = parent nuclide After Decay = Daughter nuclide (s)






42. Causes an electron to detach from an atom; occurs in radioactive reactions. Three types: 1. Alpha 2. Beta 3. Gamma






43. Refers to the amount of energy in a system that is no longer available for work. (also used to describe the amount of disorder in a group)






44. The capacity to do work






45. How do you determine the volume of an irregularly shaped object?






46. Measure of gravitational pull of Earth on an object or between two bodies






47. Substance containing two or more elements; formed by chemical reactions. Can only be separated by a chemical reaction






48. Isotopes that have not been observed to decay






49. Transfer of Energy from a body or system as a result of thermal contact. Heat consists of random motion and the vibration of atoms - molecules - & ions. Higher the temperature - greater the atomic/molecular motion






50. A system that can exchange heat and work - but not matter