Chapter 4 Flashcards
Daltons Model?
wooden spheres to represent atoms
Dalton’s Atomic Theory?
Proposed that all matter is made up of individual particles called atoms, which cannot be divided.
Thomson’s Model?
Thomson provided the first evidence that atoms are made of even smaller particles. “Plum Pudding Model”
Rutherford’ s Model
Used the Gold foil experiment to conclude that all of an atom’s positive charge is located in the center called the nucleus.
The subatomic particle with a positive charge?
Proton
Three types of subatomic particles?
- Protons (+) 2. Neutrons (n) 3. Electrons (-)
Which subatomic particle has a negative charge?
Electron (-)
Which subatomic particle has a no charge?
Neutron (n)
What is the mass of an electron?
It is said to be nonexistent because it is so small (1/1836)
What subatomic particles are located in the nucleus?
Protons and Neutrons
What is the “atomic number”?
The number of protons in an atom.
#protons = # of electrons
What is “Mass Number”?
The number of Protons & Neutrons in an atom
How do you find the number of neutrons in an atom?
Number of neutrons = mass number - atomic number
What is an “Isotope”?
Atoms from the same element that have a different number of neutrons. i.e. Oxygen-16 and Oxygen-17
Bohr’s Model of the Atom?
Diagram of an atom that looks like the solar system with the electrons circling in “energy levels”
How does an electron change energy levels
An electron can change energy levels by gaining or losing energy
What is an “Electron Cloud”?
Is a model used to describe the locations and behaviors of the electrons around the nucleus.
What is an “Orbital”?
The region of space around the nucleus where an electron is likely to be found.
How do you figure out how many orbitals are in each energy level?
How many electrons
Multiply the energy level by itself to find orbitals; 2 to get maximum # electrons
energy level 1 (11) = 1 orbital (12) = 2 electrons
energy level 2 (22) = 4 orbitals (4*2) = 8 electrons
What is an “electron configuration”?
The arrangement of electrons in the orbitals of an atom
What is the most “stable electron configuration”?
When the electrons stay in the lowest energy levels
One of the first people to state that matter is made up of atoms was
a. Democritus b. Aristotle c. Dalton d. Rutherford
c. Dalton
Dalton’s model of an atom is best described as
a. a solar system b. a solid sphere c. a plum pudding d. an electron cloud
b. solid sphere
Who provided the first evidence that atoms contain subatomic particles
a. Dalton b. Rutherford c. Thomson d. Bohr
c. Thomson
Almost all of the mass of an atom is located in its
a. protons b. electrons c. electron cloud d. nucleus
d. nucleus
An electron is a particle with
a. negative charge, found in the nucleus
b. a positive charge, found in the nucleus
c. no charge, found outside the nucleus
d. a negative charge, found outside the nucleus
d. a negative charge, found outside the nucleus
Which particle is the least massive?
a. proton b. electron c. neutron d. nucleus
b. electron
All atoms of an element have the same
a. mass number b. number of isotopes c. atomic number
d. number of neutrons
c. atomic number
The atomic number of sulfur is 16. How many electrons are there in an atom of sulfur-34?
a. 16 b. 34 c. 18 d. 50
a. 16
Atoms emit energy as light when?
a. electrons move to a higher energy level.
b. electrons move to a lower energy level.
c. protons move to a higher energy level.
d. protons move to a lower energy level.
a. electrons move to a higher energy level.
