Pages 7-18 Chapters 3-4 Flashcards
What digit is always the “uncertain” one?
The last one
If a 0 is in the begging of a measurement does it count?
Never
If a 0 is in the middle of a measurement does it count?
Always
If a 0 is in the end of a measurement does it count?
If there is a decimal
When adding and subtracting significant figures how do you get the most precise answer?
By judging the answer by the farthest point after a decimal
When multiplying and dividing significant numbers how do you get the most precise answer?
By judging by the answer with the least significant numbers
Is a Scientific Notation always less than equal too or greater than 1-9?
Equal too
What is an atom?
The smallest particle of an element that retains its identity in a chemical reaction
What were the limitations of Democritus’s ideas about atoms?
Indivisible and Indestructible
Which of the following Statements are true?
a. Atoms are the smallest particle of matter
b. The mass of an iron atom is different from the mass of a copper atom
c. Every atom of silver is identical to every other atom of silver
d. A compound is composed of atoms of two or more different elements
e. a, b and c
e. a, b and c
What is Dalton’s theory to how atoms react during a chemical reaction
Chemical reactions occur when atoms are separated from each other, joined or rearranged in a different combination. (Atoms of one element are never changed into atoms of another element as a result of chemical reaction)
What experimental evidence did Thomson have to say electrons have a negative charge?
The negatively charged electrons made the cathode ray glow
What experimental evidence did Thomson have to say atoms of all elements contain electrons
It keeps neutrality, its makes it so that every time we touch something we don’t get shocked
Would you expect two electrons to attract or repel each other
Repel
How do the charge and mass of a neutron compare to the charge and mass of a proton?
The are nearly the same
Why does it make sense that if an atom loses its electrons it is left with only a positive charge?
Because electrons cause negative charge and they are gone so all that’s left is protons and neutrons which both have positive charges
Where were the electrons in Thomson’s plum-pudding model of an atom?
In the center
How did Rutherford’s gold-foil experiment differ from his expectations?
Rutherford did not expect the Alpha particles to deflect at such a large angel
Is the charge positive or negative in the nucleus of all atoms?
Positive
In Rutherford’s atomic model, which subatomic particles are located in the nucleus?
Protons and Neutrons
Metric Conversions: Mole=
1
Metric Conversions: Molecule (or atom, formula unit or particle)=
6.02x10(23)
Metric Conversions: gram=
Mass
Metric Conversions: Liter=
22.4
