Atomic structure Flashcards
What is a chemical element?
Substance composed of only one type of atom
What is a chemical symbol?
Letter or two letters assigned to every known type of atom
Define atom
Basis of Chem
Basis of everything in universe
Matter composed of what?
Atoms
Are there pieces of matter smaller than atoms?
Yes, neutrons, protons, electrons
Are there pieces of matter smaller than neutrons, protons, electrons?
Yes, nucleons, quarks
Relative charge of a proton?
Positive one
Relative mass of a proton?
1
Position of a proton?
Nucleus
Symbol for proton?
P, P+, N+
Relative charge of a neutron?
0
Relative mass of a neutron?
1
Position of neutron?
Nucleus
Symbol for neutron?
N, N0
Relative charge for electron
-1
Relative mass of electron?
approx 1/2000
Position of electron?
cloud
Symbol for electron?
e−, β−
Describe nucleus structure
Composed of protons and neutrons
How do you know what the charge of the nucleus is?
Charge=number of protons
How small is nucleus?
Extremely small compared to atom.
Diameter average is 10 to power -15, compared to the average atomic diameter of 10 to power of -10
How many times larger than nucleus is the atom?
100,000
Diameter average is 10 to power -15, compared to the average atomic diameter of 10 to power of -10
How much of mass of atom is nucleus?
99.9%
Due to relatively large masses of protons and neutrons compared to mass of electrons.
How dense is nucleus?
Very dense
Due to large mass and small volume
Describe electron arrangement of electrons around nucleus
Move in relatively large space, often called electron cloud, outside nucleus
As negatively charged, kept moving around nucleus by attractive electrostatic forces, between them and +vly charged nucleus.
In unchanged atom, number of protons = number of electrons.
Define atomic number
Number of protons in nucleus
Define atomic mass
Number of protons and neutrons
Shell 1 is
lowest energy level
Found closest to nucleus