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Physics part I
physics part I review
| Question | Answer |
|---|---|
| What is Thomas Atom known for? | Cathode ray tubes (atom looks like plum pudding) |
| What did Ernest Rutherford do? | 1911 introduced nuclear model |
| What is Bohr Atom known for? | Minature solar system model |
| What is a quark? | photon |
| Name two new theories? | string and quantum chromodynamics |
| What is an isotope? | atom with the same # of protons but a different # of neutrons |
| What is energy? | ability to do work |
| what is mechanics? | deals with the motion of objects |
| Is weight dependent on gravity? | Yes |
| What is weight? | the force an object exerts under gravity |
| What is mass? | amount of matter contained in an object |
| What is a molecule? | smallest particle of a compound |
| What is a compound? | two or more elements joined together |
| What is an atom? | Smallest particle of an element |
| How many elements are there? | 100 approx. |
| What is matter? | substances making up all physical objects having mass, weight and that can change shape |
| The atomic # is equal to? | # of protons |
| What is the atomic mass equal to? | protons + neutrons |
| Who invented the periodic table? | Dmitri Mendeleev |
| What makes up an atom? | proton, neutron, electron |
| In 1911, Rutherford showed that the atom was composed of what? | nucleus |
| If an electron is gained or lost from an atom, what is it called??? | ionized |
| What is radioactivity? | some atoms exist in abnormally excited states characterized by an unstable nucleus. To become stable nucleus transforms into another atom |
| How is an ion pair formed? | the x-ray photon transfers its energy to orbital electron and ejects that electron from the atom. |
| What is centripetal force? | electrons revolve around nucleus in fixed orbits/shells |
| What is centrifugal force? | in the normal arom this force balances the centripetal force (autoclave) |
| What is the Law of conservation of energy? | sum total of all matter and energy is a constant |
| Can either matter or energy be destroyed/created? | No |
| Are gamma rays natural? | Yes |
| Is potential energy stored? | Yes |
| With kinetic energy random motion of molecules cause? | heat |
| A heat unit if equal to? | Calorie |
| What is work? | Result of force acting on an object |
| What is Newton's 1st Law? | A body will remain at rest unless acted on by an external force? |
| What is Newton's 2nd Law? | The force applied to move an object is equal to the mass of the object x acceleration |
| What is Newton's 3rd Law? | For every action there is an equal and opposite reaction |
| What is motion? | Velocity or acceleration |
| What is velocity? | Speed, the rate of change of position over time, i.e. 150mph |
| What is acceleration? | rate of change of velocity over timei.e. 0 to 60 in 30 seconds |
| What is power? | rate of doing work |
| What is a bindle of energy? | Photon |
| Who first came up with the atom? | greeks |
| What is Dalton Atom known for? | 1st to break down concept of the element. English school teacher |
| What did Dmitri Mendeleev do? | Periodic table |
| The periodic table is based upon what? | the number of protons in each element |
| Electromagnetic energy travels? | at the speed of light |
| Are x-rays monoenergetic? | No, they are polyenergetic |
| Are x-rays homogenous? | No, they are heterogeneous |
| Are x-rays electrically charged? | No, they are neutral |
| Can we focus x-rays with a lens? | No |
| An electron has what charge? | Negative |
| What are two different types of mechanical energy? | potential and kinetic |
| Can we convert mechanical energy into thermal energy? | Yes |
| Can we convert electrical energy into chemical energy? | Yes |
| Are x-rays able to travel in a vacuum? | Yes |
| What does the glass envelope of the tube do? | It acts as a vacuum |
| The sum of protons and neutrons in the nucleus is called what? | Atomic mass |
| What is the quantum numnber? | the number of cells |
| In the excitation process, the electrons in an atom are moved to what energy state? | higher energy |
| Do isotopes have the same or different mass number? | Different |
| Do isotopes have the same or different atomic number? | Same |