mass of the atom is concentrated) having a positive charge‚ surrounded by moving electrons carrying negative charge. Geiger and Marsden carried out an experiment to verify his proposal. The Geiger/Marsden a Particle Scattering Experiment 1. The apparatus is illustrated in the diagram below. | 2. The apparatus was in an evacuated container. The detector was a ZnS screen observed through a low power microscope. Each time an alpha particle hit the screen‚ a small flash of light was produced
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new cells. MICROSCOPES: There are two main types of microscopes: Light and Electron Electron Micrographs- shown in colour LIGHT ELECTRON Uses beam of light Magnification = x1500 Resolution = 200 nm Wide range of specimens can be used Samples are fairly quick + easy to prepare Cheaper and safer Limited resolution Limited magnification Transmission Electron Microscope (TEM) Scanning Electron Microscope (SEM) Uses electromagnets to focus beam of electrons Denser parts
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THEORY- a. All living things are composed of cells b. Cells are the basic units of structure and function of living things c. All cells are produced from other cells 4. Microscopes focus light through lenses to produce a magnified image and other microscope use beams of electrons 5. Parts of cells work together- each kind of cell structures has a different functions within a cell 6. In multi- cellular organisms cells are organized into tissues organ system 7.
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shear mixing technology to create novel colloids. The dispersed-phase particles have a diameter of between approximately 5 and 200 nanometers.[2] Such particles are normally invisible in an optical microscope‚ though their presence can be confirmed with the use of an ultramicroscope or an electron microscope. Homogeneous mixtures with a dispersed phase in this size range may be called colloidal aerosols‚ colloidal emulsions‚ colloidal foams‚ colloidal dispersions‚ or hydrosols. The dispersed-phase particles
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Questions on Units 1.1 – 1.4 on Cell Components 1 The figure below shows an electron micrograph of an animal cell. A B centriole C nucleus (a) Name and state the function of the following structures. (i) Structure A …………………………………………………………………………………………… …………………………………………………………………………………………… (ii) Structure B …………………………………………………………………………………………… …………………………………………………………………………………………… (iii) Structure C …………………………………………………………………………………………… …………………………………………………………………………………………… (6 marks)
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xray------------------------------------------------- X-ray X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers‚ corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. The wavelengths are shorter than those of UV rays and longer than those of gamma rays. In many languages‚ X-radiation is called Röntgen radiation‚ after Wilhelm
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the adaxial side of leaf. Clear tape was laid over the nail polish then removed and placed on a microscope slide and placed under a compound microscope. Three sections of each leaf were observed with the highest recorded.
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of Radiation and Radioactivity Introduction: Radiation can be defined as the propagation of energy through matter or space. It can be in the form of electromagnetic waves or energetic particles. Ionizing radiation has the ability to knock an electron from an atom‚ i.e. to ionize. Examples of ionizing radiation include: • alpha particles • beta particles • neutrons • gamma rays • x-rays Non-ionizing radiation does not have enough energy to ionize atoms in the material it interacts with. Examples
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I. INTRODUCTION Independent Study Questions 1.) What is the fundamental difference between eukaryotic and prokaryotic cells? Procaryotic cells do not contain a membrane-bound nucleus or any membrane-bound organelles. Eurkaryotic cells contain both a membrane mound nucleus and membrane-bound organelles (making them far more complex). 2.) List and describe the two domains of prokaryotic organisms. a. Bacteria- Most are a specific shape (cylindrical‚ spiral‚ or spherical). Cell
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that is better than batteries and measures just billionths of a meter. Arrays of piezoelectric nano wires could capture and transmit that waste to nano devices. These power plants are called “Nanogenerators”. It is found that when an atomic force microscope (AFM) bends a straight‚ vertical nanowire; a strain field is established‚ with the stretched surface showing positive strain and the compressed surface showing negative strain. As the tip of the AFM scans over the nano wires for each contact position
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