Flashcards
Atomic structure- year 1
Cards in this deck (38)
- 1what did Democritus propose about atomic structure between 460-370BCE?proposed that matter was made up of particles that cannot be divided further.
- 2what was Aristoles ideas on atomic structure between 384-322BCE?proposed all earthly matter was made from four elements. earth, air, fire and water.
- 3What did Robert Boyle propose about atomic structure? (1627-1691)matter is made up of tiny particles that cannot be subdivided. Putting particles together in different ways made different compounds. He studied the behaviour of gases and was the first scientist to keep accurate records
- 4what did John Dalton propose about atomic structure? (1766-1844)he named tiny particles, atoms. He said that atoms are indivisible and indestructible.
-all atoms of an element are identical
-atoms of different elements have different masses
-atoms react together to form compounds - 5what did Eugen Goldstein propose about atomic structure? (1850-1930)-cathode rays contained negatively charged particles with mass. cathode rays would be deflected by a magnetic field. He also detected heavier positive particles.
- 6what experiment did Eugen Goldstein conduct on atomic structure?he experimented with electrical discharge tubes- he passed an electric current between a cathode and an anode in a sealed tube containing gas at a very low pressure
- 7what did Joseph Thomson say about atomic structure between 1856-1937?idea that atoms contained electrons. he proposed that atoms could be divided into smaller particles. Electrons are negatively charged and are cancelled out by a sphere of positively charged material
- 8what did Ernst Rutherford propose about atomic structure? (1871-1937)mass of an atom is not evenly spread, it is concentrated in a minute central region called the nucleus. All positive charge is contained in the nucleus. The electrons circulate the rest of the atom
- 9what did henry morsely propose about atomic structure? (1888-1915)he studied x ray spectra of elements and he came up with the idea of a atomic number. He died but Rutherford did an experiment that showed the mass of the protons only accounted for half the mass of an atom
- 10what did james chadwick say about atomic structure between 1891-1974?identified the neutron
-neutrons have no charge and have the same mass as a proton. - 11What experiment did James Chadwick conduct to prove his theory on charges?he bombarded a beryllium plate with alpha particles and produced uncharged radiation on the other side of the plate. he placed a paraffin wax disc in the path of the radiation and showed that the radiation caused protons to be knocked out of the wax
- 12what did Niels Bohr propose about atomic structure? (1885-1962)electrons orbit the nucleus in energy levels which have fixed energy values.
- 13what is the relative mass of a proton and neutron?1
- 14what is the relative charge of a proton ?+1
- 15what is the relative charge of an electron?-1
- 16what are nucleons?protons and neutrons together
- 17why do protons in a nucleus not repel each other?because a strong nuclear force acts over the small size of the nucleus and binds all nucleons together.
- 18what is atomic number?the number of protons in the nucleus of an atom
- 19what is mass number?the total number of protons and neutrons in the nucleus of an atom
- 20what are isotopes?atoms of the same element with different mass numbers
- 21what do the properties of an element depend on?number and arrangement of electrons in its atoms.
- 22what are stable isotopes?isotopes that are not reactive
- 23what is relative isotopic abundance?the percentage of each isotope that naturally occur on earth
- 24what occurs in the ionisation region of mass spectrometry? what happens as a result?the sample is bombarded by high energy electrons. These knock electrons off the sample to produce a positively charged ion
- 25what is the stage that occurs after ionisation in mass spectrometry?acceleration
- 26what occurs in the acceleration stage of mass spectrometry?the ions pass through the mass spectrometer and are accelerated by an electric field.
- 27what isotope will have a lower flight time? magnesium-24 or magnesium-26magnesium-24
- 28what does the mass spectrum of an element show?-the mass number of each isotope present
-the relative abundance of each isotope - 29what is relative atomic mass?the average mass of an atom compared with 1/12 the mass of a carbon 12 atom
- 30what are orbitals?the regions of high probability
- 31how much electrons can each orbital hold?2 which spin in opposite directions
- 32how can radiation in the visible part of a spectrum be emitted?when an electrical voltage is applied to a gas at low pressure in a discharge tube
- 33what is a spin diagram?it shows the electrons in each subshell and shows the direction of all electrons
- 34what is an ionisation energy?the energy required to remove an electron from an atom in its gaseous state
- 35what are successive ionisation energies?ionisation energy values for removing the second and subsequent electrons
- 36what happens to first ionisation energies down group 2?decrease
- 37why does the first ionisation energy decrease down group 2?-the number of electrons between the outer electron and the nucleus is increasing; the electron shells shield the outer electron from the attraction of the nucleus
-the radius of each atom is increasing as you go down the group meaning the distance between the outer electron and the nucleus is increasing
- so the outer electrons are easier to remove - 38why is magnesium's first ionisation energy higher than sodium's?magnesium has one more electron than sodium meaning the 3s orbital is completed and spins in the opposite direction. there is also one more proton meaning the positive charge on the nucleus has increased
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- AS level Chemistry (Atomic structure- Year 1) Flashcards on Atomic structure- year 1, created by Tamsin Copland on 21/03/2018.
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