A&P I: CH. 2

how many elements are there in the human body? -how many are major elements? -what are the 4 most important and what percentage of the body do they make up? -how many are trace elements and what percentage of the body weight do they make up?

-26 -11 -carbon, oxygen, hydrogen, nitrogen; 96% -15; 2%

2 states of energy (each can be transformed into the other):

-Kinetic energy -Potential energy

Which 4 elements make up 96% of body weight?

-Oxygen (65%) -Carbon (18.5%) -Hydrogen (9.5%) -Nitrogen (3.2%)

3 things we need to know about a particular element:

-atomic number -mass number -atomic weight

Electrons only have about 1/2000 the mass of a proton, so the mass of an electron is usually designated as ____ amu.

0

How many protons and electrons does Hydrogen have? How many neutrons?

1 proton, 1 electron; 0 neutrons.

How many elements are recognized in total?

118

How many elements are in the human body?

26

Helium, with 2 protons and 2 neutrons, has a mass number of...

4

How many elements occur in nature? (the rest are made artificially in particle accelerator devices)

92

What percentage of body weight do O, C, H & N make up of our body weight?

96%

C-14 indicates...

A carbon isotope with a mass number of 8

Chemical energy in the form of ______ is the most useful form of energy in living systems because it is used to run almost all functional processes.

ATP

Food fuels CANNOT be used to energize body activities directly. instead, some of the food energy is captured temporarily in the bonds of a chemical called ______ ________ (____) -later, ______ bonds are broken and the stored energy is released as needed ti di cellular work

Adenosine Triphosphate (ATP)

An average of the relative weights (mass numbers) of ALL the isotopes of an element, taking into account their relative abundance in nature.

Atomic Weight

What identifies what kind of element something is?

Atomic number (# protons)

A model resembling planets revolving around the sun -useful in visualizing the structure of atoms

Bohr Model

Energy form stored in the bonds of chemical substances.

Chemical Energy

Pertains to the way the atoms interact with other atoms (bonding behavior) -account for the facts that iron rusts, animals digest food, etc.

Chemical Properties

Atoms of 2 or more elements joined to form chemical combinations

Compound

in any atom, the number of protons and number of electrons is always ______

EQUAL

Energy that results from the movement of charged particles. (found in flow of electrons along household wiring, ions, nervous system)

Electrical energy

Subatomic particles which bear a negative charge equal in strength to positive charge of the proton.

Electrons (e-)

All matter is composed of ______, unique substances that cannot be broken down into simpler substances by ordinary chemical methods -(ex: oxygen, carbon, gold, silver, iron, etc.)

Elements

What is the simplest form of matter?

Elements

The capacity to do work, or to put matter into motion

Energy

What is the simplest atom?

Hydrogen (H)

Who proposed the concept of the atom?

John Dalton (English chemist)

Energy in action -seen in constant movement of the tiniest particles of matter (atoms) as well as in larger objects (bouncing ball)

Kinetic Energy

compared with matter, energy is (more/less) tangible

LESS

Energy that is DIRECTLY involved in moving matter -(legs moving pedals while riding bike_

Mechanical energy

Subatomic particles which are neutral.

Neutrons (n0)

More modern model that is more useful for predicting the chemical behavior of atoms -depicts PROBABLE regions of greatest electron density by denser shading (electron cloud)

Orbital Model

Properties we can detect with our senses (color, texture) or measure (boiling/freezing point).

Physical Properties

The ______ model of the atom is a simplified model of atomic structure -depicts electrons moving around the nucleus in fixed, generally circular orbits -simpler to depict

Planetary Model

Stored or inactive energy that has the capability to do work, but is not presently doing so. -(batteries in unused toy, water behind dam, leg muscles while sitting on couch)

Potential Energy

Subatomic particles which bear a positive electrical charge

Protons (p+)

The 3 subatomic particles of an atom are called:

Protons, Neutrons, Electrons

Energy that travels in waves -waves vary in length; include visible light, infrared waves, radio waves, UV waves, and X rays

Radiant energy or Electromagnetic Radiation

Which 3 states does matter exist in?

Solid -(definite shape and volume) Liquid -(definite volume, but conform to shape of container) Gaseous -(neither definite shape nor definite volume)

T/F: all protons are alike, regardless of the atom considered. -same goes for all neutrons and electrons

TRUE

Synthesis is to _________ as decomposition is to _____________

anabolism; catabolism

protons + neutrons (p+n) in nuclei =

atomic mass

The ______ ______ of any atom is equal to the number of protons in its nucleus and is written as a subscript to the left of its atomic symbol.

atomic number

We designate each element by a one- or two-letter chemical shorthand called an ______ ______ -usually the first letter of the elements name -(O=oxygen, C= carbon, etc.).

atomic symbol

identical particles or building blocks that create elements

atoms

The basic unit of matter -Each element is composed of more or less IDENTICAL particles or building blocks, called ______.

atoms.

atoms of 2 or more elements joined to form chemical combinations.

compound

Energy is not ever technically LOST because it cannot be ______ or ______ -however wasted energy, such as heat given off into environment, can be ______

created; destroyed -unusable

What determines the unique physical properties of each element?

different NUMBERS of protons, neutrons, and electrons.

Energy waves (of varying in length) that include visible light, infrared waves, radio waves, UV waves, and X rays, are collectively called the ______ ______.

electromagnetic spectrum

What determines the chemical behavior of atoms?

electrons

negatively charged subatomic particles found in the electron cloud

electrons (- or e)

The number of protons is always equal to the number of ______ in an atoms, so the atomic number INDIRECTLY tells us the number of ______ in the atom as well.

electrons; electrons.

the simplest form of matter, a substance that cannot be broken down into two or more different substances

elements

In a step-by-step progression of element size, we have a series of atoms containing from 1 to 118 protons, an ______ number of electrons, and a slightly ______ number of neutrons at each step.

equal; larger

All energy conversions in the body liberate ______ -the higher, the faster the body's chemical reactions occur.

heat

Protons and neutrons are ______ particles and have approx. the same mass, designated as 1 ______ ______ ______ (___)

heavy; atomic mass unit (amu)

Since all of the ______ subatomic particles are concentrated in the nucleus, the nucleus is extremely ______, accounting for nearly the entire ______ of the atom (99.9%).

heavy; dense; mass

the word "atom" comes from the greek work meaning ______

indivisible

In the body, electrical currents are generated when charged particles called ______ move along or across cell membranes

ions

H-1 (hydrogen w/ mass number of 1) is Hydrogen's most abundant ______ -however, some hydrogen atoms have a mass of 2 or 3 amu, which means that they have one ______ and, respectively, 1 or 2 ______.

isotope -proton; neutrons

Nearly all known elements have 2 or more structural variations called ______, which have the same number of protons (and electrons), but differ in the number of neutrons they contain.

isotopes

When potential energy is released, it becomes ______ ______ and so is capable of doing work.

kinetic energy

While atoms are clusters off even smaller particles called protons, neutrons , and electrons (which can be subdivided with high-tech tools), an atom ______ the unique properties of its element when it's split into subatomic particles.

loses

the ______ of an object is equal to the actual amount of matter in the object, and it remains constant wherever the object is. in contrast, _____ varies with gravity.

mass weight

The ______ ______ of an atom is the sum of the masses of its protons and neutrons. -the mass of the electrons is so small that is is ignored. -usually indicated b y a superscript to the left of the atomic symbol

mass number

As a rule, the atomic weight of an element is approximately equal to the _____ NUMBER of its most ______ isotope.

mass; abundant

An atom's subatomic particles differ in ______, ______ ______, and ______ in the atom.

mass; electrical charge; position

Energy has no ______, does not take up ______, and can be measured only by its ______ on matter.

mass; space; effects

anything that occupies space and has mass -solids, liquids, gasses -the "stuff" of the universe

matter

All living things are composed of ______ and they all require ______ to grow and function

matter; energy

Kinetic energy does work by ______ objects, which in turn can do work by moving or pushing on other objects (example: push on swinging door sets it into motion)

moving

The smallest atoms are less than 0.1 ______ in diameter, and the largest are only about ___x as large.

nanometers(nm); 5

The nervous system uses electrical currents called ______ ______ to transmit messages from one part of the body to another.

nerve impulses

All atoms are electrically ______ because the number of protons in an atom is precisely balanced by its number of electrons (+ and - cancel each other).

neutral

neutral subatomic particles found in the nucleus

neutrons (n)

An atom has a central ______ containing protons and neutrons tightly bound together -it is surrounded by orbiting electrons.

nucleus

regions around the nucleus in which a given electron or electron pair is likely to be found most of the time, as we can never determine their exact location because they jump around following unknown trajectories.

orbitals

The ______ ______ provides a listing of the known elements and helps to explain the properties of each element.

periodic table

Every element's atoms DIFFER from those of all other elements and give the element its unique ______ and ______ properties.

physical; chemical

When chemical reactions occur that rearrange the atoms of the chemicals in a certain way, the ______ ______ is unleashed and becomes ______ ______, or energy in action.

potential energy; kinetic energy

positively charged subatomic particles found in the nucleus

protons (+ or p)

Carbon has several isotopes; each of the carbon isotopes has SIX ______ (otherwise it would not be carbon), but C-12 has ____ neutrons, C-13 has ___ neutrons, and C-14 has ___ neutrons

protons; 6, 7 ,8

FOR HELIUM: The notation 4|2 He (superscript 4, subscript 2) allows us to deduce the total number and kinds of subatomic particles in any atom because it indicates the number of ______ (atomic number [2]), the number of ______ (equal to atomic number), and the number of ______ (mass number minus atomic number) -deduce that He has ___ neutrons.

protons; electrons; neutrons -2

The ATOMIC NUMBER of any atom is equal to the number of ______ in its nucleus and is written as a subscript to the ______ of its atomic symbol.

protons; left

The nucleus is filled with ______ and ______ tightly bound together; therefore, the nucleus is ______ charged overall.

protons; neutrons; positively

The heavier isotopes of many elements are unstable_, and their atoms decompose spontaneously into more stable forms. -this process of atomic decay is called...

radioactivity

Isotopes that exhibit the behavior of radioactivity or atomic decay are called ______.

radioisotopes

The negative charge of Electrons is equal in ______ to positive charge of the proton, however an electron only has about __/______ the _______ of a proton.

strength; 1/2000; mass

Relatively speaking, matter is the ______ and energy is the ______ of the ______.

substance; mover; substance

Atomic number refers to...

the number of protons in an atom's nucleus

Protons and neutrons have a mass of 1 amu; Hydrogen only has one proton in its nucleus, so its atomic number and mass number are...

the same