Chapter 11
How many shells are represented in the presently known periodic table?
7
How does a molecule differ from an atom? Give an example.
A molecule is composed of two or more atoms bonded together: H2O.
What is a compound? Cite two examples.
Atoms of different elements with bonds between them: NaCl and H2O
What is a mixture? Cite two examples.
Atoms pressed together without bonding: air and salt and sand
Consult the periodic table and rank these atoms, from most to least, by their mass. Tantalum Niobium Dubnium Magnesium
Dubnium Tantalum Niobium Magnesium
Consult the periodic table and rank these atoms, from most to least, by their number of electrons. Tantalum Niobium Dubnium Magnesium
Dubnium Tantalum Niobium Magnesium
Consult the periodic table and rank these atoms, from most to least, by their number of protons. Tantalum Niobium Dubnium Magnesium
Dubnium Tantalum Niobium Magnesium
What is the evidence that dark matter exists?
Gravitational forces within galaxies are too great to be accounted for with ordinary matter.
Which of the following is an element? H2O Hydrogen Carbon dioxide A supernova
Hydrogen
Where in the atom is most of its mass concentrated? What is this mass composed of?
In the nucleus as protons and neutrons
Which contributes more to an atom's mass - electrons or protons? Which contributes more to an atom's size?
Protons contribute more to an atom's mass, and electrons more to an atom's size.
Rank the number of shells in these noble-gas atoms from most to least: Argon. Radon. Helium. Neon.
Radon Argon Neon Helium
Which investigator is credited for discovering Brownian motion?
Robert Brown
If you place a Styrofoam cup on the table and a bunch of BBs move around it randomly, what will happen to the cup, and why?
The cup will move randomly in different directions because the BBs will exert unequal forces on the cup in different directions.
Why did the particles jiggle around?
The particles were struck by atoms, but unequally on different sides.
What occurs when a proton and an anti-proton meet?
They annihilate each other.
How do matter and antimatter differ?
When matter and antimatter meet, they annihilate in a flash of energy.
The periodic table of the elements is a list of __________.
atoms
What is the number of orbiting electrons in each when the isotopes are electrically neutral?
cobalt-59, cobalt-60 27,27 electrons
The atomic masses of two isotopes of cobalt are 59 and 60. What is the number of protons in each?
cobalt-59, cobalt-60 27,27 protons
What is the number of neutrons in each?
cobalt-59, cobalt-60 32,33 neutrons
To become a negative ion, does an atom lose or gain an electron?
gain
Distinguish between mass number and atomic mass.
Mass number is the number of nucleons; atomic mass is the total mass of an atom.
An important feature of atoms is that they __________.
have wave properties
To become a positive ion, does an atom lose or gain an electron?
lose
The charge in the nucleus of an antimatter hydrogen atoms is __________.
negative
Dark matter is considered to be __________.
plentiful in the universe
What did Robert Brown see under the microscope?
specks of dust moving around
