Counting Atoms
NaOH
Na-1
O-1
H-1
How are the particles in as solid moving.
A solid has particles that are close together and vibrate in place.
Dmitri Mendeleev
Dalton's Theory and Analogy
Billiard Ball: Atoms are uncuttable. All atoms of the same element are alike.
How is an atom described?
NH₄Cl
N-1
H-4
Cl-1
How are the particles moving in a solid.
A liquid has particles that moves fluidly and slide past each other.
How is the periodic table organized?
Columns of elements are groups while rows of elements are called periods
Thompson's Theory and Analogy
Chocolate Chip Cookie- are positively charged substances with negatively charged particles scattered about.
What forms at the center of an atom and what is it made of?
The nucleus is the center of atoms with protons and neutrons.
NaC₂H₃O₂
Na-1
C-2
H-2
O-2
What do you need for a substance to change state?
Change in temperature
Add or Remove Energy
What does the atomic number and mass represent?
Atomic number-number of protons
atomic mass-number of protons and neutrons
Rutherford's Theory
Cherry with a pit: atoms are made mostly with empty space with a dense positively charged nucleus
What are the charges of protons, neutrons, and electrons?
Protons are positive
Neutrons have no electrical charge
Electrons are negative.
5 ZnSO₄
Zn-5
S-5
O-20
How does mass and volume differ?
Mass is anything that has weight and volume is something that is great in magnitude.
If there are 92 elements exist in nature and there are over 100 elements where did the rest of elements come from.
They were created in a lab.
Bohr's Theory and Analogy
Solar system: Electrons move in definite orbits around the nucleus.
What is the smallest unit of an element and how does it different from the smallest unit of a compound?
Double Points: How are Elements and Compounds Similar
The smallest unit of an element is a compound and the smallest unit of a compound is a molecule.
They are similar because they are both pure substances.
2Sr₃ (PO₄)₂
Ca-1
C-4
H-6
O-4
List two scientific principles that relate to phase changes.
1. Air has mass and volume.
2.Matter is anything with mass.
What is the key difference between the modern periodic table and the first periodic table.
The modern periodic table increases by number not atomic mass the first periodic table increased by mass not number.
Current Theory and Analogy
Cotton ball theory: Electrons do not move in orbits but instead at high speeds to form an electron cloud.
What determines the charge of an ion?
An ion is negative if there are more electrons than protons.
An ion is positive if there are more protons than electrons.