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Structure of Atom
Junior cycle science ch 24
| Question | Answer |
|---|---|
| materials around us are made of | atoms |
| an atom is the smallest particle of an element ...... | that still has the properties of that element |
| John Dalton imagined atoms as ... | very small marbles |
| to see atoms use | an electron microscope |
| subatomic particles are found | inside in an atom |
| protons have a | positive charge |
| electrons have a | negative charge |
| neutrons have | no charge |
| protons and neutrons both have a relative mass of | 1 |
| protons and neutrons are found in the | nucleus |
| electrons are found | outside the nucleus on an electron cloud or shell |
| the mass of an electron is much smaller or bigger than a proton | smaller |
| Neils Bohr is the scientist who first said that | electrons move in fixed paths called shells or orbits |
| all atoms are neutral therefore they have the same number of | protons and electrons |
| the atomic number of an atom is equal to the | number of protons or electrons in the atom |
| mass number is the | number of protons plus the number of neutrons |
| to calculate the number of neutrons in an atom... | subtract the atomic number from the mass number |
| the only element with atoms with no neutrons is | Hydrogen |
| The nuclear formula for an atom shows both | mass number and atomic number |
| Atoms of an element are all | the same |
| The periodic table is an arrangement of elements in order of... | increasing atomic number |
| scientist who first drew the periodic table was | Dmitri Mendeleev |
| vertical columns in the periodic table are called.... | groups or families |
| horizontal rows of elements are called | periods |
| Group 8 elements are called ...... | Noble or inert gases |