Flashcards in Chapter 10 - Atoms Deck (45)
All matter consists of what?
Where are protons and neutrons found?
In the nucleus
Where are electrons found?
Orbiting the nucleus in electron clouds
State the charge of each subatomic particle: Proton, Neutron, Electron
Proton: Positive (+)
Neutron: No charge (0)
Electron: Negative (-)
The atomic number is equal to the number of _____ in an atom
In an element that has no overall charge, the atomic number also helps you identify what? Why?
The number of electrons; the number of protons (+) and electrons (-) must equal to create no overall charge in the element. So if the atomic number is 5 in an element (5 protons), then the element also has 5 electrons.
What is the mass number?
The sum of the numbers of protons and neutrons in the nucleus of an atom.
What is the atomic mass of an element?
The number that averages all of the masses of isotopes of an element together.
If O-10 takes up 50% of all Oxygen (O) atoms in nature and O-4 takes up 50% of all Oxygen (O) atoms in nature, than what is the atomic mass for oxygen?
10 * 50% = 5
4 * 50%. = 2
7 atomic mass units (amu)
The number after the hyphen in an atom (H-12) is the atom's what?
How do you find the number of neutrons in an element?
Subtract the atomic number(# of protons) by the atomic number
Element:Atomic Mass :: Atom:_____
What defines an element(no other element has the same ____)?
Its atomic number
Two atoms have the same atomic number but a different number of neutrons(and therefore a different mass number). What are theses elements called?
The electron is a lot (larger, smaller) than a proton or neutron
If an atom has more protons than electrons, then it is what?
A positively charged ion
Describe gravitational force.
All objects attract each other. The larger the mass and the greater the distance between objects, the stronger the gravitational force.
Describe electromagnetic force.
Objects with alike charges repel and objects with different charges attract.
Describe strong force.
The close distance between the neutrons and protons in the nucleus of an atom causes strong force and keeps the nucleus together. Without the neutrons, there would be no buffer between the protons, causing them to repel each other.
Describe weak force.
In some unstable atoms, neutrons have the ability to change electromagnetic charges; it can turn into a proton or electron. Weak force plays a key role in radioactive elements
Who thought that you could keep cutting a particle infinitely?
Who thought that you would end up with a particle that couldn't be divided?
Who experimented with different substances and developed an atomic theory?
Who found that atoms could be divided into further parts and discovered the electron of the atom? He also created the plum-pudding model.
Who used a gold-foil experiment to discover the small, dense nucleus of the atom?
Atoms consist mostly of _____
Who discovered that electrons can jump between certain paths, or energy levels?
What are electron clouds?
Regions around the nucleus where electrons are likely to be found.
Up to how many electrons can each energy level hold?