Chemistry Flashcards
(21 cards)
What is chemistry?
Chemistry is the science that deals with matter (properties, composition, structure, interactions) and the energy involved in these interactions.
18th Group Name?
Inert Gases
How many atoms are in HO2
1 Hydrogen Atom
2 Oxygen Atoms
Is KI an Element or Compound?
Compound, Potasisum and Iodine
What atoms are in MgCl3
1 Magnesene atom
3 Chlorine Atoms
What were the two sets of information that chemists were trying to put
together in designing the periodic table?
The masses of the elements, and the chemical families.
An element
A pure substance with only one kind of atom
Period
A horizontal Row across on the periodic table
Group
A vertical Row on the periodic table
Family
A coloum/group of atoms with similar chemical properties
Valence shell
The outermost electrons in an element
What did Mendeleev do about the “missing elements” in his periodic table?
He left spaces for them in the future
What was another reason why it was difficult to create an organization that made sense?
Many elements had not yet been discovered.
Elements _ exist naturally
Elements _ have only ever exist in a labratory
Elements 1 to 94 exist naturally
Elements 95 to 224 have only ever been synthesized in a laboratory
(The bottom two rows Lathaides and Actinides)
How do you determine the number of electrons in an Element?
The period number is equal to the number of electron shells. (Except transition metals)
How do you know how many Valence Electrons are in an Element?
Elements in the same column have the same number of electrons in their outermost shell called Valence Electrons. (Except transition metals)
3 categories of matter
Metals, non-metals, metaliods
How do you tell how many Protons are in an Element?
of protons = Atomic Number
How do you tell how many Electrons are in an Element?
of electrons = Atomic Number
How do you tell how many neutrons are in an Element?
of Neutrons = Atomic Mass – Atomic Number
4 statements of Daltons Atomic Theory
Dalton Atomic Theory stated:
- All matter is made up of small particles called atoms.
- Atoms cannot be created, destroyed or divided into smaller
particles. - All atoms of the same element are identical, but they are different
from the atoms of other elements. - Compounds are created when atoms of different elements link
together in definite proportions.
