Final exam Flashcards
(29 cards)
What is the difference between physical and chemical change?
A chemical change is a permanent change and it is irreversible in nature.
A Physical change is a temporary change and it is reversible in nature. It affects only physical properties i.e. shape, size, etc. ..
When comparing the reactants and products of a chemical reaction, how would you know that a chemical
change has occurred?
There are five signs of a chemical change:
Color Change.
Production of an odor.
Change of Temperature.
Evolution of a gas (formation of bubbles)
Precipitate (formation of a solid)
What is the difference between a physical property and a chemical property
- chemical properties are characteristics that describe a substance’s ability to change into different substances
- physical properties are characteristics that can be observed without changing it into another substance.
element and a compound
Elements cannot be broken down by chemical reactions. Compounds can be easily separated into simpler substances by chemical reactions.
homogeneous and heterogeneous mixtures
Heterogonous mixtures are ones in which their constituents do not mix uniformly, while homogenous mixtures are ones in which they mix uniformly.
JJ. Thomson
experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons.
Ernest Rutherford
Rutherford’s contribution was the discovery that atoms contain a positively charged nucleus much smaller than the actual atom.
John Dalton
Dalton’s atomic theory suggested that all matter was comprised of indivisible and indestructible atoms with distinct masses and properties, the combination of which determined the physical nature of their constituent elements.
Mass of electron
0
Mass of proton
1
Mass of neutron
1
What are the only particles that contain mass in an atom, hence, dictate the mass number of an atom?
Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons.
What are the particles responsible for the volume of an atom?~
The volume of the atom as a complete structure, the electrons contribute the most to it with its orbitals.
What is a neutral atom?
An atom that has equal number of protons and electrons is called a neutral atom.
Isotope
atoms of the same element that have the same number of protons but a different number of neutrons, meaning that their mass number varies
How to find neutrons ?
subtracting the atomic number from the atomic mass.
What is the difference of the electrons in the 1s orbital compared to the electrons in the 2s orbital of a carbon
atom?
The 2s orbital is at a higher energy level. The 2s orbital can hold more electrons. The 1s orbital can have only one electron.
Explain why electrons start filling the 1st energy level of an atom first before they fill the 2nd energy level of
the same atom.
We fill the 1s first because it is lowest in energy, then the 2s because it is next higher in energy, and then the 2p is even higher, and so on.
How many total electrons can fit in an s, p, d, f orbitals?
s orbital can contain up to two electrons
p orbital can contain up to six electrons,
the d orbital can contain up to 10 electrons
f orbital can contain up to 14 electrons
relationship of nu and lambda in the speed of light formula
Lambda and nu have an inverse relationship.
Mendeleev contribution was and the Periodic Law
Mendeleev created his version of the periodic table listing the most known elements at the time by their ascending atomic mass.
electronegativity
is a measure of the tendency of an atom to attract a bonding pair of electrons.
atomic radius
the total distance from an atom’s nucleus to the outermost orbital of electron
ionization energy
a measure of the difficulty in removing an electron from an atom or ion or the tendency of an atom or ion to surrender an electron.
