Atomic Theory

Edit Answers
123456789101112131415
Across
  1. 2. of an atom, which states that the electrons float in positively-charged material. This model was named after the plum-pudding dessert.
  2. 5. In 1933, James Chadwick (1891-1974) discovered a new type of radiation that consisted of...
  3. 8. that combine to form the great variety of substances consist themselves of aggregations of similar subunits (atoms) possessing nuclear and electron substructure characteristic of each element.
  4. 11. that all things can be accounted for by innumerable combinations of hard, small, indivisible particles (called atoms)
  5. 12. Divided atoms in a process called...
  6. 14. a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
  7. 15. All matter consists of indivisible particles called atoms. Atoms of the same element are similar in shape and mass, but differ from the atoms of other elements. Atoms cannot be created or destroyed. Atoms of different elements may combine with each other in a fixed, simple, whole number ratios to form compound atoms.
Down
  1. 1. model of an atom consisting of a central, positively charged nucleus containing nearly all the mass and surrounded by a cloud of negatively charged planetlike electrons.
  2. 3. are a type of radiation emitted by the negative terminal, the cathode, and were discovered by passing electricity through nearly-evacuated glass tubes.
  3. 4. the theory that all matter is made up of tiny indivisible particles (atoms). According to the modern version, the atoms of each element are effectively identical, but differ from those of other elements, and unite to form compounds in fixed proportions.
  4. 6. states that if two elements form more than one compound between them, the masses of one element combined with a fixed mass of the second element form in ratios of small integers.
  5. 7. English chemist
  6. 9. Greek Philosopher
  7. 10. Roman philosopher and poet
  8. 13. is a negatively charged subatomic particle that can be either bound to an atom or free (not bound). An electron that is bound to an atom is one of the three primary types of particles within the atom -- the other two are protons and neutrons. Together, electrons, protons and neutrons form an atom's nucleus.