Chapter 2 Flashcards
The word atom comes from the Greek word atomos meaning:
“unable to cut.”
the building blocks that comprise all forms of matter.
Atoms
carbon (C) comes from the___ word _____, meaning ______
(1) Latin
(2) carbo
(3) “coal” or “charcoal;”
_____ was named for the planet Neptune;
neptunium (N)
einsteinium (Es) was named for scientist _____;
Albert Einstein
californium (Cf) was named for the state of _____.
California
are named for people, places, and things.
Elements
Each ____ is identified by a one- or two-letter symbol.
element
When two letters are used in the element symbol, the first is _____ and the second is ______.
uppercase
lowercase
Long ago it was realized that groups of elements have similar properties, and that these elements could be arranged in a schematic way called the:
periodic table
These are shiny substances that conduct heat and electricity. Metals are ductile, meaning they can be drawn into wires, and malleable, meaning they can be hammered into shapes.
Metals
These have properties intermediate between metals and nonmetals.
Metalloids
These are poor conductors of heat and electricity.
Nonmetals
The elements in the periodic table are divided into three categories:
metals, nonmetals, and metalloids.
The solid line that begins with ____ and angles in steps down to ______ marks the three regions corresponding to these groups.
boron B
astatine (At)
All metals are located to the __ of the line.
left
All nonmetals except hydrogen are located to the ___.
right
Metalloids are located:
along the steps.
Four nonmetals _____ comprise ____ of the mass of the human body, and are called the ___
oxygen, carbon, hydrogen, and nitrogen
96%
building-block elements
_____ are the elements that form water, the most prevalent substance in the body.
Hydrogen and oxygen
______ are found in the four main types of biological molecules
Carbon, hydrogen, and oxygen
four main types of biological molecules are
proteins, carbohydrates, lipids, and nucleic acids.
Proteins and nucleic acids
contain the element ____ as well.
nitrogen
Seven other elements, called the ______ or _____, are also present in the body in much smaller amounts
major minerals or macronutrients
What’s the percentage of the major minerals that are present in the body?
0.1-2% by mass
______ are present in body fluids.
Sodium, potassium, and chlorine
These occur in proteins
Magnesium and sulfur
These are present in teeth and bones.
calcium and phosphorus
This is also contained in all nucleic acids, such as the DNA that transfers genetic information from one generation to another.
Phosphorus
At least _____ of each macronutrient is needed in the daily diet.
100 mg
Many other elements occur in very small amounts in the body, but are essential to—
good health.
These are required in the daily diet in small quantities, usually less than _____.
Trace elements or micronutrients
15 mg
Each trace element has a specialized function that is important for proper _____
cellular function.
This is needed for hemoglobin, the protein that carries oxygen in red blood cells, and myoglobin, the protein thatstores oxygen in muscle.
iron
This is needed for the proper functioning of many enzymes in the liver and kidneys
Zinc
This is needed for proper thyroid function.
iodine
Although most of the trace elements are metals, nonmetals like _____ are micronutrients as well.
fluorine and selenium
Bullding-Block Elements
(4)
Oxygen (0)
Carbon(C)
Hydrogen(H)
Nitrogen (N)
Trace elements
(14)
Arsenic(As)
Boron (B)
Chromium (Cr)
Cobalt(Co)
Copper(Cu)
Fluorine (F)
lodine (I)
Iron (Fe)
Manganese (Mn) Molybdenum(Mo)
Nickel (Ni)
Selenium (Se)
Silicon(Si)
Zinc (Zn)
Major minerals
Potassium (K)
sodium(Na)
chlorine (CI)
Magnesium (Mg)
sulfur (S)
Calcium (Ca)
phosphorus(P)
A _____ uses element symbols to show the identity of the elements forming a compound and subscripts to show the ratio of atoms contained in the compound.
chemical formula
These are used to identify the common elements that form compounds.
Color-coded spheres
Sometimes the spheres will be connected by “sticks” to generate a ____ for a compound.
ball-and-stick representation
At other times, the spheres will be drawn close together to form a____
space-filling representation.
human cheek cellcontains about ____
1x10^16
An ____ is composed of three subatomic particles. Which are?
atom
Proton
Electron
Neutron
A ____, symbolized by p, has a positive (+) charge.
proton
An _____, symbolized bye , has a negative (-) charge
electron
, symbolized by n , has no charge.
A neutron
Of the118 elements currently known, ___ are naturally occurring and the remaining ____ have been prepared by scientists in the laboratory.
90
28
These have approximately the same, exceedingly small mass,
Protons and neutrons
The mass of an electron is much less, ___ the mass of a proton.
1/1,836
The ___ is a dense core that contains the protons and neutrons. Most of the mass of an atom resides in the ____.
nucleus
The ______ is composed of electrons that move rapidly in the almost-empty space surrounding the nucleus.The ______ comprises most of the volume of an atom.
electron cloud
While the diameter of an atom is about ____, the diameter of a nucleus si only about _____
10^-10 m
10^-15 m
Proton mass (g)
1.6726 x 10^-24
Neutron mass (g)
1.6749 x 10^-24
Electron mass (g)
9.1093 x 10^-28
Proton mass (amu)
1
Neutron mass (amu)
1
Electron mass (amu)
Negligible
Proton charge
+1
Neutron charge
0
Electron charge
-1
These charges repel.
Negative and positive
This charge attracts.
Opposite charges
the ______, which defines the mass of individual atoms relative to a standard mass.
atomic mass unit
One atomic mass unit (amu) equals ____ the mass of a carbon atom
one-twelfth
The mass of a carbon atom has that has _______
six protons and six neutrons
(Carbon atom) 1 amu = ____
1.661 × 10^-24 g
one proton has a mass of ____, a value typically rounded to 1 amu.
1.0073 amu
One neutron has a mass of ____, a value also typically rounded to 1 amu
1.0087 amu
The mass of an ____ is so small that it is ignored.
electron
Every atom of a given type of element always has the same number of protons in the nucleus, a value called the ____, symbolized by Z.
atomic number
The _______ = the number of protons in the nucleus of an atom
atomic number (Z)
The periodic table is arranged in order of increasing atomic number beginning at the
upper left-hand corner.
The _____ determines the identity of a nelement.
atomic number
The ____, symbolized by A, is the sum of the number of protons and neutrons.
mass number
In a neutral atom, the atomic number (Z) =
the number of protons= the number of electrons.
These are atoms of the same element having a different number of neutrons.
Isotopes
The _____ is the weighted average of the mass of the naturally occurring isotopes of a particular element reported in atomic mass units.
atomic weight
A row in the periodic table is called a _____. Elements in the same row are similar in size.
period
A column in the periodic table is called a ____. Elements in the same group have similar electronic and chemical properties.
group
The chemical properties of an element are determined by the number of _____ in an atom.
electrons
_____ do not move freely in space; rather, an/a ______ is confined to a specific region, giving it a particular energy.
Electrons
Electrons occupy ____ energy levels. The energy of electrons is_____; that is, the energy is restricted to specific values.
discrete
quantized
The electrons that surround a nucleus are confined to regions called the:
principal energy levels or shells.
Electrons ___ to the nucleus are held more tightly and are lower in energy.
closer
Electrons ___ from the nucleus are held less tightly and are higher in energy.
farther
The ____ a shell is from the nucleus, the ____ its volume becomes, and the more electrons it can hold.
farther
larger
The maximum number of electrons is given by the formula
2n^2
The number of electrons that can occupy a given shell is determined by the value of
n
