Chapter 2: Atoms and Molecules Reading Flashcards
(35 cards)
What has a tremendous impact on a molecule’s properties?
atoms
What is the atom composed of?
A nucleus that has protons and neutrons surrounded by an electron cloud
What is a common misconception about the electron cloud?
Electrons follow regular orbits around the nucleus. They actually act like clouds of negative charge that surround the nucleus
What is the charge of an atom? why?
0 because the charge of the proton and electron are opposite and there is an equal amount in each atom.
What is the atomic number?
The number of protons in an atom
What are atoms of the same element with a different number of neutrons called?
Isotopes
What to subatomic particles have similar masses?
Protons and Neutrons
What unit is appropriate for the atomic scale?
Atomic Mass Unit (amu)
How de we calculate amu and what is that number called?
Protons plus neutrons. This is called the mass number
What changes between isotopes? What stays the same?
Mass number. Atomic Number
What are the two important functions of a mass spectrometer?
- Takes a stream of microscopic particles and sorts them according to mass
- Measures the number of particles with a given mass
What happens when there is a peak at a particular mass?
The sample analyzed has a component with that mass.
What are isotopic abundances?
The percentages describing the relative amounts of each isotope.
What do the symbols in writing an isotope stand for?
X is the element, A is the mass number, Z is the atomic number.
What is atomic weight? How is it calculated?
The average mass of an atom of a particular element. Calculated with the relative abundance of each isotope (amu x percent abundance)
What are the horizontal rows on the periodic table called? Vertical columns?
Periods. Groups.
What happens as you move across a row?
Important properties of elements vary
What happens to the density of elements as you move across a row?
They generally increase
What patterns are seen in elements in the same column?
They exhibit similar chemical properties
What are the name of the columns of elements?
First Group - Alkali Metals
Second Group - Alkaline Earth
Group 17 - Halogens
Last Group- Noble Gases
Elements that separate these two parts are called transition metals
Bellow the periodic table are lanthanides and actinides
What are the three classifications of an element?
Metals, Nonmetals, and Metalloids
What are the properties of metals?
Shiny, malleable, and ductile
They can also conduct electricity
What are the properties of non-metals?
Most molecules that make up the body
Not shiny. malleable, or ductile
Do not conduct electricity
Tend to form cations
What are metalloids?
Along a diagonal path across the periodic table
