Lesson 9, Classification of Matter Flashcards
https://www.youtube.com/watch?v=dggHWvFJ8Xs
What are the two main categories of matter?
Pure substances and mixtures
What is a pure substance
They cannot be further broken down. They are either elements, only made of one kind of atom, or compounds.
What is a mixture?
A mix of elements and compounds
Eg. AIR
What is a homogenous mixture
Looks uniform, even if there are many parts.
Eg. Fruit punch
What is a heterogenous mixture?
You can see all the parts
E.g. Salad
What is the purpose of the periodic table?
To organize all of the elements in the world in a logical manner
What are the three subatomic particles?
Protons, Neutrons and electrons
What are protons?
A subatomic particle with a positive charge and a mass of approximately 1 atomic mass unit
What is the relationship between atomic number and protons in an atom?
They are the same!
What is the first rule for drawing Bohr-Rutherford diagrams?
Label the number of protons and neutrons within the nucleus
This establishes the atomic identity and mass of the element.
How are electrons represented in Bohr Rutherford diagrams?
Electrons are represented as black dots
This visual representation helps in identifying electron distribution.
What is the maximum number of electrons that can be held in the 1st orbital?
2 electrons
What is the maximum number of electrons that can be held in the 2nd orbital?
8 electrons
What is the maximum number of electrons that can be held in the 3rd orbital?
8 electrons
What is the maximum number of electrons that can be held in the 4th orbital?
18 electrons
In a neutral atom, what must be true about the number of protons and electrons?
The number of positive charges must equal the number of negative charges
In ions, how does the number of protons compare to the number of electrons?
protons ≠ #electrons
What does the atomic number represent in the context of protons and electrons?
protons (atomic number) = number of electrons
Fill in the blank: The 1st orbital holds a maximum of _______ electrons.
2
Fill in the blank: The 2nd orbital holds a maximum of _______ electrons.
8
Fill in the blank: The 3rd orbital holds a maximum of _______ electrons.
8
Fill in the blank: The 4th orbital holds a maximum of _______ electrons.
18
What is a neutron?
A subatomic particle with no charge and a mass of about one atomic mass unit
What is an electron
It is a negatively charged subatomic particle with a mass of 0 atomic mass units
Where are electrons located?
Orbiting the nucleus
What is the relationship between groups and valency?
Each group has the same amount of valance electrons
