Chemistry Exam
Terms
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- Mixture can be broken down into ___________ and ____________.
- homogeneous and hetrogeneous
- What did the Greeks bring to the development of the atomic theory?
- Greeks developed the concept of an atom and named the atom
- Neils Bhor decided the electrons did what?
- electrons orbited the neucleus in energy levels
- Define atom
- smallest units of matter that retains the properties of matter
- What did John Dalton?
- all elements made of small spherical shapes called atoms and atoms from one element differ from others.
- Who invented the periodic table and how was the table arranged?
- Demitri Mendleev and by atom mass numbers
- Example of a element, compund and mixture.
- oxygen, water, salad dressing
- What did Thompson dicover?
- atoms had a positive center with negativ electrons attached to it.
- Why is group 18 called noble gases?
- they won't bond with any other elements and they are all stable
- How is the periodic tbale aranged today
- atomic number
- Name groups 1,2,3-12,17,18
- 1-Alkali metals 2-alkaline earth metals 3-12-transition elements 17-hatogens 18- noble gases
- How many periods and groups are on the table?
- 7 periods and 18 groups
- How does the group number help you draw dot models? How does the period number help you draw atom models?
-
valence electrons
amount of energy levels - Why does the periodic table give average atomic mass numbers?
- because there might be an istope for that element
- Define isotope and valence electrons
-
isotope-atoms of the same element with diff.#'s of neutrons.
valence electrons-outer most electrons - Substances can be broken down into __________ and ___________.
- elements and compounds
- Matter can be classified in what two ways?
- a substance and mixture
- What are the two types of chemical bonds and how can you tell the difference between the two?
-
ionic bond and covalent bond.
ionic bond is a transfer covalent bond is a share. - what is the area that electrons are in called?
- electron cloud
- which phose of matter has the least kenetic energy?__________
- solida
- In an ionic bond metals become ________ ions and the nonmetals becom _______ ions.
- positive and negative
- define ion
- a positively or negatively charged atom
- Rutford's gold foil experiment brought the discovery of what?
- said an atom had empty space with a positive core called the neucleu surronded by electrons.
- which phase of matter has the least knetic energy?
- solids