Chapter 2 - Basic Chemistry & Cells

Question 1

Element

Answer 1

Substance that cannot be broken down into substances with different properties; compound of only one type of atom

Question 2

Isotopes

Answer 2

One of two or more atoms with the same atomic number but have a different atomic mass due to the number of neutrons

Question 3

Hydrogen Bond

Answer 3

Weak bond that arises between a slightly positive hydrogen atom of one molecule and a slightly negative atom of another or between parts of the same molecule

Question 4

Temperature

Answer 4

My thermostat?!?

Question 5

Buffer

Answer 5

Substance or group of substances that tend to resist pH changes of a solution, thus stabilizing its relative acidity and basicity

Question 6

Matter

Answer 6

Anything that takes up space and has mass

Question 7

Ionic Bond

Answer 7

Chemical bond in which ions are attracted to one another by opposite charges

Question 8

Ion

Answer 8

Charged particle that carries a negative or positive charge

Question 9

Covalent Bond

Answer 9

Chemical bond in which atoms share one pair of electrons

Question 10

Solute

Answer 10

Substance that is dissolved in a solvent, forming a solution

Question 11

Compound

Answer 11

Substance having two or more different elements united chemically in fixed ratio

Question 12

Electron

Answer 12

Negative subatomic particle, moving about in an energy level around the nucleus of an atom

Question 13

Solvent

Answer 13

Liquid portion of a solution that serves to dissolve the solute

Question 14

Solution

Answer 14

Fluid (the solent) that contains a dissolved solid (the solute)

Question 15

Atom

Answer 15

Smallest particle of an element that displays the properties of the element

Question 16

Electronegativity

Answer 16

Ability of an atom to attract electrons toward itself in a chemical bond

Question 17

Cohesion

Answer 17

Clinging together of water cells

Question 18

Atomic Number

Answer 18

Number of protons within the nucleus of an atom

Question 19

Atomic Mass

Answer 19

Mass of an atom equal to the number of protons plus the number of neutrons within the nucleus

Question 20

Polar Molecule

Answer 20

A polar molecule has a positive and negative end because of electronegativity. H2O, for example, is a polar molecule because 1) it has lone pairs 2) the oxygen is pulling the electrons from the hydrogen into its vicinity making it have a slightly negative charge while the two hydrogens have a slightly positive charge.

Question 21

Surface Tension

Answer 21

his question could be best answered through an example of a drop of water on a dry non absorbent surface. If u observe closely the the water droplet will not spread easily. This ability of holding the surface molecules together is called surface tension

The ability of the molecules of a substance which are at the surface to form intermolecular bonds which binds them together is called surface tension

Question 22

Acid

Answer 22

Molecules tending to raise the hydrogen ion concentration in a solution and to lower its pH numerically

Question 23

Base

Answer 23

Molecules tending to lower the hydrogen ion concentration in a solution and raise the pH numerically

Question 24

Heat

Answer 24

Type of kinetic energy; captured solar energy eventually dissipates as heat in the environment

Question 25

Know the structure of the atom

Answer 25

Basically, an atom consists of a very tiny nucleus surrounded by electrons. To understand the basic structure of an atom, you really need to know that the nucleus and electrons have opposite electrical charges. The nucleus is positively charged, and the electrons are negatively charged. Opposite charges attract; this is why the electrons stay bound to the nucleus. If there are an equal number of negative (electron) charges as there are positive charges in the nucleus (which come from the protons in the nucleus), the atom will will have no charge. The nature of the electron states is addressed by quantum mechanics. Electrons have wave properties. Without getting too deeply into the quantum theory, quite a lot about atoms and their properties can be rationalized using the Bohr model of the atom.

Question 26

List and EXPLAIN the properties of water

Answer 26

Water (H2O) is the most abundant compound on Earth's surface, covering about 70 percent of the planet. In nature, water exists in liquid, solid, and gaseous states. It is in dynamic equilibrium between the liquid and gas states at standard temperature and pressure. At room temperature, it is a tasteless and odorless liquid, nearly colorless with a hint of blue. Many substances dissolve in water and it is commonly referred to as the universal solvent. Because of this, water in nature and in use is rarely pure and some of its properties may vary slightly from those of the pure substance. However, there are also many compounds that are essentially, if not completely, insoluble in water. Water is the only common substance found naturally in all three common states of matter and it is essential for all life on Earth.[4] Water usually makes up 55% to 78% of the human body.

Question 27

Know how the pH scale works

Answer 27

The pH scale goes from 0-14. 7 is when the pH of something becomes neutral, for instance, water. The concentration of hydrogen ions determine the acidity or basicity, so water has a concentration of 1x 10 to the negative seventh power. A pH of 6 is a concentration of 10, and gets 10 times more concentrated as the pH gets decreased by 1. A pH of 8 has the concentration of 1/10, and gets 10 times less concentrated as the pH gets increased by one.

Question 28

Six elements that are predominant in living things

Answer 28

``` Hydrogen - 1 Carbon - 6 Nitrogen - 7 Oxygen - 8 Phosphorus - 15 Sulfur - 16 ```