Chemistry 105: Test One

electromagnetic radiation:

a source of light that can/cannot be seen

hypothesis:

a tentative explanation (educated guess)

How are ions formed?

by gaining or losing electrons

one hundredth of a gram:

centigram

ions:

charged particles; atoms with a net negative or positive charge

Positron

has the same mass as a beta particle, but a charge of 1+; ejected at 90% the speed of light; used in a medical radiation procedure called positron emission tomography

neutral atom:

has the same number of electrons and protons

Greek Prefix for 9

nona

Greek Prefix for 8

octa

Gamma Rays:

radio waves

one-thousandth of a meter:

1 millimeter

What is a beta particle?

a negatively charged particle ejected from the nucleus of a radioisotope; has the same mass and charge as an electron

alpha particle:

a particle with two protons and two neutrons

Greek Prefix for 10

deca

Mass Fomula:

density(volume)

Greek Prefix for 1

mono

Positron Particle:

positive electron

pico(p)

0.000000000001 = 10^-12

nano(n)

0.000000001 = 10^-9

micro(u)

0.000001 = 10^-6

milli(m)

0.001 = 10^-3

centi(c)

0.01 = 10^-2

deci(d)

0.1 = 10^-1

one billion meters:

1 gigameter

Which one is the greater amount of energy? 1kcal or 1kJ?

1 kcal = kilocal

mega(M)

1,000,000 = 10^6

giga(G)

1,000,000,000 = 10^9

kilo(k)

1000 = 10^3

deka(da)

10^1

Alpha particle:

2 protons + 2 neutrons

Which one is the greater amount of energy? 4.184 cal or 1J?

4.184 cal

Avogadro's number:

6.02 x 10^23 atoms or molecules

Diatomic atoms:

7 atoms that occur as homonuclear diatomic molecules (two) in their gaseous states: hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. (start at atomic number 7 & make a 7 including hydrogen)

octet

8 valance electrons which creates a stable electron arrangement

Atomic symbol of Nitrogen:

N

Do all elements have isotopes?

NO

Atomic symbol of Nickel:

Ni

Atomic symbol of Palladium:

Pd

Iron

a trace element that transports oxygen from the lungs to different parts of the body and is also part of many enzymes and is essential for growth, healing, immune function and synthesis of DNA.

What is the difference between accuracy and precision?

accurate measurements fall near the true value while precise measurements are grouped together

Name the 4 types of radioisotopes:

alpha, beta, gama, and positron

What does each period on the periodic table represent?

an energy level

theory:

an experimentally explanation of an observed behavior

Matter:

anything that has mass and occupies space

Radioactive isotopes:

atoms that emit nuclear change

What is an isotope?

atoms with the same number of protons, but a different number of neutrons

how do atoms bond?

based on valance electrons

Why is most of the mass of an atom located in the nucleus?

because the mass is the number of protons plus the number of neutrons

An example of a chemical change (change is chemical composition) that involves starting with a liquid and ending up with a gas:

burning gasoline (combustion)

Physical changes that a piece of copper wire could undergo:

can be cut into smaller pieces, can be coiled into different shapes, can be melted using heat

Physical properties of a piece of copper wire:

can conduct electricity, is ductile, is malleable, is brown-gold in color, is shiny

Gas:

constantly moving; can be compressed; will take volume and shape of container

Greek Prefix for 2

di

Significant figures:

digits in a measurement that are reproducible when the measurement is repeated, plus the first uncertain digit

Gives an example of a substance that sublimes:

dry ice (solid carbon dioxide)

Gama Particle:

electromagnetic radiation

Beta Particle:

electron

skeletal structure:

electron dot structure

Bohr's atomic model:

electrons orbit the nucleus specific to the hydrogen atom; when energy is absorbed, the electron gets "excited" and jumps energy levels

trace elements:

elements that the body needs, but only in a limited amount

Law of conservation of energy:

energy is neither created or destroyed in an isolated system, it just changes from one form to another or transfers from one part of the world to another

Give an example of a physical change that involves starting with a liquid and ending up with a gas:

evaporation

Liquid:

fixed volume; will take shape of container (no fixed shape)

Ionic Compounds:

formed from metals & nonmetals; have a neutral charge; transfer/exchange electrons; written in their empirical formula

Anion

gain ions; negatively charged particle

Greek Prefix for 7

hepta

Name two trace elements:

iron and zinc

one millionth of a gram:

nanogram

Name and give the atomic symbols for the four most abundant elements in the human body:

oxygen (O), carbon (C), hydrogen (H), nitrogen (N)

Greek Prefix for 5

penta

Accuracy:

related to how close a measured value is to a true value

Specific gravity:

relates the density of a substance to that of water

is the statement "what goes up must come down" a scientific law or a scientific theory? Explain.

scientific law; scientific laws are statements that describe things that are consistently & reproducibly observed

Periodic Table Group Family:

share in both chemical and physical properties

What are the three states of matter?

solid, liquid, gas

Specific gravity formula:

specific gravity = density of substance/density of water

Greek Prefix for 4

tetra

Energy:

the ability to do work and transfer heat

Physical change:

the chemical composition of matter is not altered

Deposition:

the conversion of a gas directly into a solid (reverse process of sublimation)

Sublimation:

the conversion of a solid directly into a gas (w/o becoming a liquid)

Adequate Intake (AI):

the daily intake of a nutrient believed to be sufficient to meet the needs of people (due to unreliability of experimental data, the percentage of people covered by a particular AI is uncertain)

Recommended dietary allowances (RDA):

the daily intake of nutrients that are sufficient to meet the needs of 97%-98% of healthy people

What are the two parts to scientific notation?

the decimal part and the exponential part

Kinetic energy:

the energy of motion

Heat of vaporization:

the heat required to evaporate a liquid

Heat of fusion:

the heat required to melt a solid

molar mass:

the mass in grams of one mole of atoms of the element; equal to its atomic weight in amu

Why does the nucleus of an atom have a positive charge?

the nucleus is made up of protons (+) and neutrons (O) so the overall charge is positive (+)

Atomic number:

the number of protons in an atom's nucleus

nuclear radiation:

the particles & energy released in a nuclear change

Mass number:

the total number of protons and neutrons in an atom's nucleus

ROY G BIV

the visible spectrum (colors we CAN see)

Cation

lose electrons; positively charged ion

Polyatomic Ions:

many atoms that come together with the same charge

How do you get the estimated mass of an element?

mass of the isotope X percent abundance + every isotope present

Volume Formula:

mass/density

Density Formula:

mass/volume

Solid:

matter is closely packed together; fixed volume; fixed shape

one million grams:

megagram

Binary/Covalent compounds:

molecular/covalent; formed from two nonmetals or a nonmetals and a metalloid; share electrons; form covalent bonds

one million meters:

1 megameter

hecto(h)

100 = 10^2

Molecule:

collection of atoms

Atomic symbol of Sulfur:

S

Precision:

a measure of reproducibility

Greek Prefix for 6

hexa

Potential energy:

stored energy

How is an alpha particle similar to a helium nucleus?

they are identical because both have two protons, two neutrons, and a 2+ charge

Zinc

trace element that forms enzymes and improves immune function, helps clot blood, maintains sense of taste and smell, keeps skin healthy and enables normal growth and development.

Greek Prefix for 3

tri

infrared

type of light that WE give off

How is a beta particle different than an electron?

unlike an electron, a beta particle is ejected from the nucleus of a radioisotope at up to 90%. the speed of light; the mass of a beta particle is equal the mass of an electron; the charge of a beta particle is 1+

Atomic symbol of Gold:

Au

Atomic symbol of Xenon:

Xe

How are positrons and beta particles different?

a beta particle has a charge of 1- while a positron has a charge of 1+

How is a theory different from a hypothesis?

a hypotheis is made based on observations or currently known facts, while a theory is an experimentally explanation of an observed behavior. If a hypothesis survived repeated testing, it may become a theory (theories explain while hypothesis are a tentative explanation)