Atoms, Bonding, and the Periodic Table Flashcards
Describe the size of Atoms
Atoms are so small that a particle of dust could have 10 million billion atoms
Why did scientists create models of atoms
To describe atoms because they are so small
What is at the center of Atoms?
Tiny, dense nucleus containing protons and neutrons
What surrounds the nucleus of Atoms?
A cloudlike region of moving electrons
Describe the space of Atoms
Contains a lot of volume, huge space, compare to the center of a stadium to the seats
What charge do protons have?
Positive +1, number is equal to electrons, helps to make an atom neutral
What charge do electrons have?
Negative, -1, number is equal to protons, helps to make an atom neutral
What chage do neutrons have?
They don’t have a charge, they are 0
Do protons and neutrons have the same mass?
Yes, they are equal
What is the unit of measure that scientists use to measure mass of atoms?
Atomic mass units (amu)
Describe the atomic number
atoms of an element has the same number of protons, The 3 of protons in the nucleus is the atomic number
Where are the electrons of atoms found?
In different energy levels
What do you call electrons that have the highest energy?
Valence electrons, involved in chemical bonding
What helps to determine the chemical properties of elements?
The number of valence electrons in each atom
What makes valence electrons so unique?
each atom of an element has a certain number of valence electrons, that number is specific to that element
What is a diagram that includes the symbol for the element surround by dots called?
Electron dot diagram (each valence electron has a dot)
How many valence electrons do atoms need to have in order to be stable (nonreactive)
8
Why do atoms form bonds?
To become more stable so they have 8 valence electrons
What is the force of attraction that holds atoms together as a result of the rearrangement of electrons between them
chemical bond
What happens to the valence electrons when atoms bond?
The electrons may be transferred or shared between bonds
How is the Periodic table arranged?
In order of increasing atomic number, the number of valence electrons increases from left to right.
What is another name for the row on the Periodic Table?
Periods
What is another name for the columns on the Periodic Table?
Groups
Each _______ begins with an element that has 1 valence electron.
period
The elements in each group have similar _____
properties
Each element in Periods 2 and 3 has one more valence electron than the element to its ______
left
Where are the noble gases located on the Periodic Table?
Group 18, they have 8 valance electrons (not Helium with 2)
What makes Noble gases unique?
They are stable, they do not gain or lose electrons, or share them with other atoms. They do not react easily with other elements
Where are the metals on the Periodic Table?
Blue section of the table
How do metals react?
By losing their valence electrons
The reactivity of metals ________ from left to right across the table
decreases
Describe the alkali metals
- located on the far left side in group 1
- most reactive in its period
- 1 valence electron
- so reactive that they can cause an explosion when added to water
Where are the nonmetals located on the table?
In the orange section
Describe the nonmetals
- become stable when they gain or share enough electrons
- combine with metals by gaining electrons
- combine with other nonmentals and metalloids by sharing electrons
Describe the halogens
- in group 17
- 7 valence electrons
- react easily with other elements
Describe metalloids
- lie along with zigzag line in the periodic table
- can lose or share electrons
- has some properties of metals and some of the nonmetals
Describe Hydrogen
- in group 1 on the table because it has 1 valence electron
- Considered a nonmetal
- very different from the properties of alkali metals
- shares electrons when forming compounds
