Intro to Chemistry Block 3

Question 1

2-1. Define Matter and provide examples and the characteristics for the three states of matter.

Answer 1

Matter is anything that occupies space and has mass with the exception that some things can be smelled, felt and seen.
Solid - bones and teeth
Liquids - blood and plasma
Gases - air we breathe (neither volume or shape)

Question 2

2-2. Define Energy and provide examples and the characteristics for the four states of energy.

Answer 2

Energy is the capacity to do work or put matter in.to motion. No mass, does not take up space, can only be measured by its effect on matter

Chemical - when chemical reactions occur rearranges atoms of the chemicals for the potential energy to be unleashed and become kinetic energy or energy in action. Ex. food we eat - ATP

Electrical - results of the movement of charged particles, nerve impulses to transmit messages; Ex. electrical impulses across the heart stimulate it to contract.

Mechanical - results in energy directly involved in moving matter. Ex. riding a bike, your legs provide the mechanical energy that moves the pedals.

Radiant or Electromagnetic - energy that travels in waves. Ex. visible light, radio waves, x-rays

Question 3

2-3. Compare and contrast Kinetic and Potential Energy. How is energy converted to other forms in the body?

Answer 3

Kinetic energy is energy in action.

Potential energy is energy that is stored (inactive)

Question 4

2-4. Define Element. How many elements exist? What elements comprise over 96% of the Human Body?

Answer 4

Element - all matter is composed of elements, unique substances that can not be broken down into simpler substances by ordinary chemical methods.

There are 118 elements recognized

H-hydrogen, C-carbon, O-oxygen, N-nitrogen compromise 96% of the human body

Question 5

2-5. Define/ describe atom. Name and define the characteristics of the three subatomic particles. What subatomic particles are found in the nucleus?

Answer 5

Atom - each element is composed of more or less identical particles called atoms.

Atom = indivisible

Protons, Neutrons and Electrons

Protons and Neutrons are found in the nucleus.`

Question 6

2-6. Describe orbitals.

Answer 6

Orbitals are the regions around the nucleus where the electrons are most likely to be found.

Question 7

2-7. Define and describe how elements are identified. Include a description of atomic number, mass number, atomic weight, and isotopes.

Answer 7

Elements are identified by their:

Atomic Number - is equal to the number of protons in the nucleus

Mass Number & Isotopes - sum of the masses of the protons and neutrons

Atomic Weight - average of all isotopes of an element

Question 8

2-8. Label the following figure identifying element name (atomic symbol), atomic number, and atomic weight.

Answer 8

See picture.

Question 9

2-9. What is a radioisotope? Why are radioisotopes used in a clinical. setting? Provide examples

Answer 9

Radioisotope are isotopes that are heavier and become unstable and their atoms decompose spontaneously into more stable forms.

In clinical settings they are used for diagnosis, to localize and illuminate damaged or cancerous tissue.

Ex. iodine is used to determine size and activity of thyroid gland and detect thyroidal cancer.

Question 10

2-11. In as few words as possible, list the three ways in which mixtures differ from compounds.

Answer 10

In mixtures there is no chemical bonding, No change in atoms or molecules, they are only physically intermixed. Mixtures can be separated by physical means (straining, filtering)

Compounds can be separated into their constituent atoms only by chemical means.

Question 11

2-12. What is the maximum number of electrons an orbital can hold? (2) Why is the number of electrons that partially fill the outermost shells important for an atom?

Answer 11

There can only be eight (8) maximum electrons in an orbital.

The number of electrons that partially fill the outermost shell is important for bonding behavior.

Question 12

2-13. What is the octet rule (aka. rule of eights)? Why is it important in discussing the chemistry of life?

Answer 12

The Octet Rule (rule of 8) is the rule to chemical reactivity participate in bonding. The Octet Rule is important when discussing the chemistry of life because what types of atoms they attract, for bonding and chemical interactions.

Question 13

2-14. What is a chemical bond?

Answer 13

A chemical bond is the result from attractive forces between atoms. Share or transfer electrons.

Question 14

2-15. Compare and contrast Ionic Bonds and Covalent Bonds.

Answer 14

An ionic bond is a chemical bond between atoms formed by the transfer of one or more electrons from one atom to another. DONATE

A Covalent bond is a bond which the shared electrons occupy a single orbital common in both atoms. SHARE ex. Oxygen

Question 15

2-16. Describe Hydrogen Bonds.How do they differ from Ionic and Covalent Bonds?

Answer 15

A Hydrogen bond is formed when a Hydrogen atom, already covalently linked to one electronegative atom (usually nitrogen or oxygen) is attracted by another hungry atom so that a bridge forms between them, ATTRACT

Question 16

2-17. Describe the differences between anions and cations. How are anions and cations created/produced?

Answer 16

An Anion is the atom that gains electrons is the electron receptor.

A Cation is the atom that loses electrons is the electron donor.

Question 17

2-18. Compare and contrast Polar and Non-polar Molecules. Provide three examples of each.

Answer 17

Non-Polar molecules (two identical atoms sharing electrons) are when molecules are formed and are electronically balanced. Because they do not have separate (+) and (-) poles of charge. O2=non-polar

Polar molecules (different atoms) are unequal electron pairing during the forming of molecules especially when nonsymmetrical molecules containing atoms with different electron attracting abilities. H2O=polar

Question 18

2-19. What information does a chemical reaction contain? Provide three examples of chemical reactions that occur?

Answer 18

A chemical reaction contains:
a.) reactants
b.) # of reactants
c.) product
Ex. Methane, Hydrogen Gas, Carbon Dioxide, Photo Synthesis

Question 19

2-20. Define and describe in detail:

            (1) synthesis reactions
            (2) decomposition reactions
            (3) exchange reactions
            (4) redox reactions.

Answer 19

Synthesis reaction occurs when atoms or molecules combine to form a larger, more complex molecule. A synthesis reaction always involves bond formation.

Decomposition reaction occurs when a molecule is broken down into smaller molecules or its constituent atoms.

Exchange reactions involves both synthesis and decomposition. Bonds are made and broken.

Redox reaction or Oxidation reduction reaction are decomposition reactions in that they are the basis of all reactants in which food fuels are broken down for energy. Also special type of exchange because electrons are exchanged between reactants.

Question 20

2-21. List and describe four factors that influence chemical reaction rates and explain how these factors increase and decrease reactions rates.

Answer 20

The factors that influence chemical reaction rates:

a. ) Temperature - increase temperature of a substance increases kinetic energy of its particles and the force of their collision.
b. ) Concentration - progress more rapidly when the reacting particles are present in higher concentrations because the chance of successful collision is greater.
c. ) Particle size - smaller particles move faster at the same temperature and tend to collide more frequently and more forcefully. The smaller the reacting particles, the faster a chemical reaction goes at a given temperature and concentration.
d. ) Catalysts - are substances that increase the rate of chemical reactions with out themselves becoming chemically changed or part of the product.

Question 21

2-10. Define/describe molecule. Compare and contrast a compound and a mixture. Describe the difference between solutions, colloids and suspensions.

Answer 21

Molecule - two or more atoms held together by chemical bonds.

Compound - two or more different atoms bind 0 chemically pure

Mixture - two or more components are physically intermixed (nature)

Solutions - gases, liquids or solids exactly the same composition or make up throughout.

Colloids - composition is dissimilar in different areas of the mixture

Suspensions - are colloid mixtures with large, often visible solutes that tend to settle out.