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Electrons in atom
Spanish speaking countries and their capital
Question | Answer |
---|---|
Who is John Dalton ? | English chemist and school teacher who formulated a theory to describe the structure and chemical reactivity of matter in terms of atoms. |
Who is Democritus ? | Greek philosopher who was among the first to suggest the existence of atoms. |
What is the atomic number? | The atomic the number of protons in the nucleus of an element |
What is the periodic table? | An arrangement of elements according to the similarities in their properties |
What is the mass number ? | Equals the number of neutrons plus the number of protons in an atom |
What is a group? | A vertical column of elements in the periodic table |
What is an isotope ? | Atoms that have the same number of protons but different numbers of neutrons |
What is the atomic mass unit ? | 1/12 the mass of a carbon-12 atom |
What is atomic mass ? | The weighted average of the atoms in a naturally occurring sample of an element |
What is a period? | A horizontal row of the periodic table. |
What is ground state? | Ground state is the lowest energy position allowable for an electron |
What are electrons? | They are negatively charged subatomic particles |
What is a cathode ray? And who used it in the experiment? | A stream of electrons produced at the negative electrons of a tube , containing a gas at low pressure. Thompson. |
What are protons? | Positively charged subatomic particles |
What are neutrons? | Subatomic particles with no charge |
What is an excited state? | The energy level of an electron that had absorbed energy |
What is the nucleus? | The central core of the atom , which is composed of protons and neutrons |
What is an atom? | The smallest particle of an element that retains its identity in a chemical reaction |
What is Daltonâs atomic theory ? | Matter is made up of atoms, atoms combine in while number ratios to form compounds, atoms separate combine, or rearrange in chemical reactions. Major contributor of modern atomic theory |
What were some mistakes of Daltonâs theory? | He believed atoms were indivisible and all atoms are identical. That was incorrect because of isotopes |
What did JJ Thompson discover? | He discovered the electron. Also found that the electron was much smaller than the smallest atom. He created the plum pudding model and cathode Ray |
What did the plum pudding model propose? | The model proposed that there was a spherical ball with a positive charge while there was negatively charged electrons in it |
What did Robert Millikan discover? | He found the accurate measurement of the charge and mass of electron. Showed that electrons are part of matter. |
Who preformed the oils drop experiment? | Robert Millikan |
What did Ernest Rutherford discover? | He discovered the protons ,Most of the atom is just empty space, very small size of atom has a positive charge. |
Who did the gold foil experiment? | Ernest Rutherford |
What is the Quantum mechanical model? | Current model |
What did DeBrogolie discover? | All matter travel in waves. |
What is the relationship between mass and the wavelengths? | Mass and wavelength is inversely |
What did Heidenberg discover? | He created the Uncertainty principle |
What is the uncertainty principle? | Cannot know the location or speed of an electron with complete certainty |
What is Schrodingerâs wave equation? | Treated electrons as particles moving in waves and found the probability of where they would be. |
What did Neilâs Bohr contribute to science? | Organized electrons into discrete energy levels, as electrons jump between levels and energy is released as light- explains spectroscopy |
What mistakes did Neilâs Bohr have in his theory? | Thought electrons were in orbits around the nucleus |