Basics of Chemistry(Test 1) (copy)

matter

material substance that occupies space and has a mass.

Mass

the amount of coherent matter an object contains

Weight

measure of pull of gravity on an object

Energy

The capacity of a system to perform work or put an object into motion.

Potential energy

Inactive Energy stored in an object or system

b. Kinetic energy

The energy in motion that sets particles in motion

Chemical energy

The potential energy stored in chemical bonds of compounds such as ATP, glucose, fatty acids etc.

Electrical energy

The flow of charged particles across wire or cell membranes, such as in neurons, pacemaker in the heart etc.

Mechanical energy

The form of energy which physically moves the object.

Radiant or electromagnetic energy

The energy that comes from the sun that travels in waves in the form of X-waves,g-rays, and Visible light

Law of Thermodynamics

Governs the transfers and transformation of energy

First Law of Thermodynamics

Law of conservation of energy, the energy can neither be created nor destroyed, therefore, “the total energy of an isolated system remains constant

Second Law of thermodynamics

That with every transfer or transformation of energy, the capacity of the system to perform work will decrease because there will be less useful energy available at the end of transfer process than at the beginning

Entropy

Which is a measure of disorder in a closed system, increases whenever there is a transfer of energy or breakdown of an organized system

Useless energy in the sense that it is not available to perform workse that it is not available to perform work

Enthalpy

It indicates how much heat and work was added or removed from the system or can be described as the heat of reaction

Free Energy(G) or Useful Energy

denotes the maximum amount of work that a system can perform at constant temperature

Mass of one Dalton”1.67 x 10^-27 kilogram”

Proton and Neutrons

9.1 x 10^-31kilogram

Electron

Planetary model

Based on fixed, generally circular orbits in which the electrons move

Orbital model

Electron cloud in which electron are moving around the nucleus

Atomic mass

It is the average of relative mass (atomic mass) of all the isotopes of an element, in which mass of each isotope is multiplied by the relative abundance of that isotope in nature

Atomic Number

Represent the number of protons found in an Element

Isotopes

Each of the two or more forms of the same element which contain equal numbers of protons but different numbers of neutrons in their nucleus and have different relative atomic mass but possess similar chemical properties.

Radioisotopes

Radioactive Electrons that decay into stable state over time

Energy shells

The rings around the Nucleus which the Electrons move around in

Octet Rule

The Tendency of having 8 electrons in the outermost shell and accepting more electrons from bonds of other Electrons to get eight electrons in its outermost region

Valance

refers to the number of electrons an atom can use in bonding. In other words, the number of electrons an atom can donate or accept to make a chemical bond.

Covalent Bonds

The electrons pairs are shared between the atoms to make single (involving one electron from each element), double (involving two electrons from each element) or triple (involving three electron from each element), or tetra (involving four electron from each element) covalent bond.

Nonpolar covalent bonds

The electrons are shared equally.

Covalent bond

The electrons are shared unequally between the two nonmetal atoms which have different electronegativity

Ionic Bond

When the electron is transferred from a donor to an acceptor. For example, Na (sodium) donates one electron to Cl (chlorine), which makes sodium electro-positive

Hydrogen Bond

Formed between molecules of polar substances in which one member of the bond pair is hydrogen

Anabolic Reactions

In these reactions synthesis of complex molecules occurs from simple molecules due to the formation of chemical bonds.

Catabolic Reactions

In these reactions, breakdown of complex molecules into simple molecules occurs and the chemical bonds are broken.

Redox reactions

The oxidation-reduction are important chemical reactions which take place in the cells. A substance may be oxidized by following methods;

Electron Carriers or Electron Accepters

Found in the mitochondria are called cytochromes such as Cytochrome, the electrons removed from a substrate,and are accepted

NADH2

These hydrogen carriers play an important role in the glucose oxidation during cellular respiration.

Cytochrome

Which are found in the cristae of mitochondria, and help generate ATP by utilizing the energy released during glucose (or lipids) oxidation

Water

60% of the body weight is water, of which 40% is contained inside the cells

intracellular fluid (ICF)

Water is inside the cells

extracellular fluid (ECF)

Water outside the cells

Plasma

5 percent of the water outside the cells.partially-ionized gas, containing ions, electrons, and neutral atoms.

Surface Tension

The water molecules form a web of H-bonds with each other, and this cohesiveness allows surface of the water to resist external force

surfactant

Decreases the surface tension and allows expansion of the alveoli when the air flows-in

Alveolus

Which allows expansion of both small and large alveoli for effective gas exchange

Atelectasis

If the baby is born prematurely, the lack of surfactant causes the lungs to collapse

Specific Heat

The amount of heat needed raise the temp of a substance by 1 unit

The heat of vaporization

is the amount of heat needed to convert 1 g of water (or another liquid) into vapor, without a rise in the temperature of the water (or another liquid).

Sweat

Water-based and serves as an effective coolant when it evaporates from the skin.

Heat Fusion

The amount of heat absorbed by each gram of ice when it melts or is given up by each gram of water when it freezes. The heat of fusion of water is about 79 calories/g.

Molarity

the concentration of a solute in a solution expressed as the number of moles of solute per liter of solution

Avogadro’s Number

6.02 x 1023. It represents the number of molecules in one Mole of the substance.

Osmolarity

Is defined as the number of osmoles of solute present per liter of solution. In other words, osmolarity represents the concentration of a solution expressed as the total number of solute particles per liter

Acidic solution

H+ > OH--, therefore, acids contain a large number of H+ ions (proton donors) and fewer OH- ions.

Basic solution

Solution: H+ < OH-, therefore, bases contain a smaller number of H+ ions and a large number OH- ions.

Neutral solution

H+ = OH-, therefore, neutral solutions contain equal number of H+ and OH- ions.

Buffers

can donate or accept H+ thus maintaining pH

bicarbonate (in the blood or intestine), phosphates and proteins

Important buffers in the body

Kidneys

Play an important role in maintain blood pH between a narrow range of 7.2 to 7.3 to prevent the blood from being too acidic

PH scale

1-14

Acidic

7-14

7.0

Neutral

<7.0

Basic

Which of the following is the smallest unit of weight;

nanogram

Useless energy, which is not available to perform work is termed as..

Entropy

Anion

gains an electron

Canion

loses an electron

Addition of Oxygen, Removal of Hydrogen,Loss of Electrons

oxidization methods

Removal of Oxygen,Addition of Hydrogen, increased electrons

Oxidation reduced methods

Heat Fusion of Water

79 calories/g

hydrophobic substances

nonpolar and are insoluble in water

hydrophilic

Water dissolves polar substances

spontaneous reaction

is a reaction that favors the formation of products at the conditions under which the reaction is occurring.

exothermic

means a decrease in the energy of the system as energy is released to the surroundings as heat.

Trace Elements

a chemical element present only in minute amounts in a particular sample or environment

Atomic mass

no. of protons + neutrons

COHN elements

96 percent

³H

2 Neutrons

C, H, O, N, Ca and P.

98 percent