Chapter 4 Flashcards
(106 cards)
According to Dalton’s Atomic theory Elements are composed of _________.
atoms; tiny, hard, unbreakable spheres
According to Dalton’s Atomic theory all atoms of a given element are ___________.
identical; atoms of different elements are different, every carbon atom is identical to every other carbon atom, but carbon atoms are different than sulfur atoms
According to Dalton’s Atomic theory atoms combine in _____, __________ ratios to form ________ of ___________
- simple
- whole number
- molecules
- compounds
Atoms combine as whole atoms because…
atoms are unbreakable
Each molecule of a compound contains the exact same ______ and ________ of atoms
- types
- numbers
- law of constant composition* - i.e. H2O will always contain 2 Hydrogens and 1 Oxygen; Hydrogen peroxide will always have 2 hydrogens and 2 oxygens
According to Dalton’s Atomic theory atoms are not _______ or ________ into another type during a chemical rxn.
- broken
- changed
*all atoms present before the reaction are present after
According to Dalton’s Atomic theory atoms are not ______ or _______they are just ________
- created
- destroyed
- rearranged
- therefore the total mass will remain the same this is called the law of conservation of mass.
Can atoms change into a different type of atom during a chemical reaction?
No, atoms of one element do not change into Adams of another element in a chemical reaction.
Lead cannot be turned into gold via chem. rxn
Scientists such as JJ Thomson and others showed that atom had pieces called __________
electrons
Thomson discover about electrons?
He discovered that electrons are smaller than atoms and carry a negative charge of 1-
1 e-
One electron with a charge of one minus
5 e-
Five electrons with a total charge of five minus
Chemical reactions _______atoms.
rearrange
CH4 + O2 —–> CO2 + H2O
A (3g) + B (5g) = C + D (?)
8g
law of conservation of mass
Two kinds of charge_______and ______.
positive
negative
If you have to positively charged magnets will they attract or repel?
repel, because like charges repel and opposite charges attract.
an atom has the same number of protons and electrons what is the atom’s charge?
the atom is neutral.
If something has no charge, or the same number of charges what is it called?
neutral
What are the significant points of Rutherford’s interpretation of the nuclear model?
- the atom contains a tiny dense center called the nucleus.
- The nucleus has essentially the entire mass of the atom.
- The nucleus is positively charged.
- the electrons move around in the empty space of the atoms surrounding the nucleus.
how much space does the nucleus of an atom take up?
1/10 trillionth of the volume of the atom
Trying to contribute to the mass of an atom?
Yes but the amount of mass they contribute is so insignificant that they practically give no mass to the atom.
Positively charged particles are called __________.
Protons
*Protons have a positive charge of 1+
Who proposed that there was a positively charged particle in the nucleus of an atom that has the same amount of charges an electron?
Rutherford
he discovered this based on measurements of the nuclear charge of elements
1p+
one proton