Chemistry Flashcards
the study of matter, its chemical and physical properties and the chemical and physical changes it undergoes
Chemistry
a specific substance that can’t be broken down into simpler substances by chemical reactions
Element
How many elements are on the periodic table? How many are naturally occurring? How many are unstable?
118 total
94 naturally occurring
24 unstable
the arrangement of the elements that communicates important information about each of the elements and how they relate to one another
Periodic Table
What 4 things are included in each square on the periodic table?
- Atomic Number
- Chemical Symbol
- Element Name
- Atomic Mass
What does the Atomic Number represent?
protons in an atom of an element
How is the Atomic Mass calculated?
Atomic Mass = # proton + average # neutrons
How do you calculate the average number of neutrons?
Average # Neutrons = Rounded Atomic Mass - Atomic Number
the smallest component of an element that retains all of the chemical properties of that element
Atom
the central region of all atoms that contain protons + neutrons and are orbited by electrons on the outside
Nucleus
positively charged particles inside the nucleus of an atom
Protons
negatively charged particles that orbit around the outside of the nucleus of an atom
Electrons
particles with no charge inside the nucleus of an atom
Neutrons
electrons in the outer electron shell and are important for chemical reactions
Valence Electrons
Balanced atoms have what electron to proton ratio?
1:1
Atoms have the same # of electrons as protons
atoms of the same element that have the same number of protons but a different number of neutrons
Isotopes
How do you write proton vs electron charges?
Proton = +1
Electron = -1
when an atom contains an equal number of protons and electrons
Neutral Atom
Isotopes of an element are chemically _____ , BUT may have ______ stabilities
identical
different
How would you write normal magnesium (atomic mass of 24) vs an isotope of magnesium (atomic mass of 25)? And how many protons and neutrons would each have?
Mg-24
12 protons + 12 neutrons
Mg-25
12 protons + 13 neutrons
holds the atoms of two joined elements together
Chemical Bond
What part of the atom forms bonds?
Electrons
How many electrons can the first 3 orbitals hold?
First - 2
Second - 8
Third - 18