SNC 1D Development of the Atomic Theory Match each name with



Development of the Atomic Theory

Match each name with the appropriate description below. Each name may be used more than once.

(a) Aristotle (b) Niels Bohr (c) James Chadwick


(d) John Dalton (e) Democritus (f ) Dmitri Mendeleev (g) Ernest Rutherford (h) J.J. Thomson 1. determined that the mass of a proton approximately equals the mass of a 2. discovery of the electron 3. discovery of the neutron 4. discovery of the proton 5. theory that an atom is mostly empty space 6. gold-foil experiment providing evidence of the nucleus in an atom 7. hypothesis (in the 1800s) that all matter is made up of indivisible atoms 8. organization of elements in the periodic table according to their properties

and atomic numbers

9. prediction of the properties of elements unknown at that time 10. hypothesis that all atoms of an element are identical 11. idea that an atom is a positively charged sphere, with electrons evenly

distributed throughout it, like the raisins in a plum pudding

12. hypothesis that atoms of different elements are different 13. demonstrated that electrons move around the nucleus in fixed orbits 14. stated that the nucleus of an atom is surrounded by a cloud of electrons 15. demonstrated that the nucleus of an atom contains most of its mass and is

positively charged

16. theory of an “indivisible” atom


17. statement that a neutral atom has the same number of protons and 18. hypothesis that matter is conserved during a chemical reaction 19. statement that the distance of an electron from the nucleus depends on the

energy of the electron

20. claim that all matter is made from earth, water, air, and fire 21. theory that each electron orbit can hold a maximum number of electrons