1
Atomic radii are often given in picometers, which are 10^-12 m. T/F?
True
smallest basic unit
The atom
According to Dalton's atomic theory, how are atoms of different elements characterized?
different from each other
Who discovered that all of an atom's positive charge is concentrated in the nucleus?
Ernest Rutherford
Adding more protons to the nucleus increases the atomic mass but does not affect the atomic radius. (T/F)?
Bonus if you know what is the atomic mass
False
Atomic mass= protons + neutrons
What happens to atomic radius as you move down the periodic table?
It becomes larger
Atoms can bond together to form molecules, some of which are compounds. T/F?
True
Explain the difference between compounds and molecules
molecules are two or more atoms.
Compounds are two or more elements.
What is the atomic radius defined as?
The distance from the nucleus to the outermost electrons
What happens to the atomic radius as atomic number increases? (Left to Right)
Decreases
What happens when two like charges are brought close together?
They repel each other
What is an example of a compound?
H2O
what did Thomson discover through his experiments with cathode rays?
Electrons
What does electronegativity refer to?
The ability to attract electrons in a chemical bond
What did Bohr's model of the atom address?
Why electrons do not fall into the nucleus
What are allotropes or give and example on one.
Different forms of the same element that exist in the same physical state but have different atomic arrangements and, consequently, different properties
/ phosphorus
Electrons in a hydrogen atom are physically identical to electrons in a uranium atom. T/F?
true
Can mass be created or destroyed during a chemical reaction?
No. Only rearranged
What is the modern view of the electron?
A wave of probable positions
What is the energy required to remove an electron from an atom called?
Ionization Energy