Question | Answer |
Chemistry | The study of what substances are made of and how one substance can be changed into another. |
Matter | Anything that takes up space and has mass and weight. |
Weight | A measure of the pull of gravity on an object. |
Mass | The amount of matter that makes up an object. |
Gram | A metric unit used to measure an object's mass. |
Density | The amount of matter (mass) in one unit of volume (space.) |
If two objects have the same volume but different densities, which object will weigh more? | The object with the most density. |
Volume | Space. |
Atom | A tiny particle form which all substances are composed; the smallest particle of an element. |
Electron cloud | The cloud-like shield around an atom's nucleus formed by the atom's fast moving electron; prevents other atoms from moving into the same space. |
Neutrons | A particle that helps make up the nucleus of an atom. |
Proton | A positively charged particle that helps make up the nucleus of an atom. |
Like charges(like two positive charges)attract, true or false? | False. |
What do you call something that lacks an electrical charge? | Neutral. |
Hydrogen atom | The simplest kind of atom having a single electron whirling about a single proton. |
Helium atom | Contains two of each kind of particle. |
Carbon atom | Six electrons move about a nucleus of six protons and six neutrons.(This atom has two shells.) |
Shell | A group of electrons in an atom that orbit at roughly the same distance from the nucleus. |
Oxygen atom | Has eight protons, and eight neutrons, and eight electrons. |
Sodium | Has three electron shells. |
Atomic number | The number of protons in an atom. |
Every element has its own _______ __________. | Atomic number |
Element | A substance that is composed of only one type of atom. |
Compounds | A substance that is composed of more than one type of atom bonded together. |
Each element is composed of a ________ ______ ___ _______. | Unique type of atom |
Plutonium | the most abundant of the transuranium elements. |
Osmium | A metal that is the densest elements. |
Periodic table of elements | A chart constructed by Dmitri Mendeleev to arrange the element in such a way as to group similar elements together. |
The blocks of color in the periodic table indicate the ______ _______ ______ ___ ______. | Three main groups of elements |
In the periodic table, elements colored in blue are what? | Metals. |
In the periodic table, elements colored in yellow are what? | Nonmetals. |
In the periodic table, elements colored in pink are what? | Semimetals. |
Name 5 important metals. | Gold,Platinum,silver,copper,iron,or aluminium. |
Name three metal's uses. | Nickel-used to make nickel coins
Lead-used to make car weights
Zinc-used to make flashlight batteries |
Metals | A large group of elements that are typically shiny, with a silvery color, and are good conductors of electricity. |
Nonmetals | The element in the periodic table that are not classified as metals or semimetals. |
Name 3 important nonmetals. | Sulfur,Carbon,Oxygen |
Name three nonmetal's uses. | Oxygen-makes up the air
Sulfur-important in body chemistry
Carbon-makes up diamonds |
Hydrogen | The very first element in the periodic table; a colorless and odorless gas at room temperature. |
About ____% of the atmosphere is nitrogen, and about ____% is oxygen. | 78,21 |
Oxygen | A colorless and odorless gas that animals and people require in order to live. |
Nitrogen | A colorless, odorless gas that is much less prone than oxygen to react with other elements; nitrogen compounds are used in fertilizers, rocket fuel, and explosives. |
Protein | A complex molecules found in living things that are necessary for life. |
Carbon | A nonmetal that is a basic building block of all living organisms. |
Sulfur | A nonmetal element that is an odorless, yellow solid at room temperature; called brimstone in the Bible. |
Sulfuric acid | A highly corrosive chemical used in car batteries and chemical manufacturing. |
Phosphorus | A nonmetal element that is a wax-like soled with two forms, white phosphorus and red phosphorus; compounds of phosphorus and oxygen oxygen known as phosphates are used as fertilizers and food preservatives. |
Silicon | A gray semimetal that in pure form is used to make computer chips and is an ingredient in common sand, the mineral quartz,and glass. |
Alkali Metals | The metals in the first (far left) column of the periodic table, such as sodium and potassium. |
Sodium and potassium | Common in the rocks, soils, and oceans of the earth, although neither occur naturally in pure form. |
Sodium hydroxide | An important compound of sodium also known as lye or caustic soda; formula is NaOH. |
Alkaline earth metals | The metals in the second column of the periodic table, such as calcium and magnesium. |
Calcium | A silver-gray element that is the most common alkaline earth metal; and ingredient in limestone, cement, teeth and bones. |
Calcium carbonate | A calcium compound that is the chief ingredient in seashells, limestone, and concrete. |
Magnesium | An alkaline earth metal that is strong but lightweight and is used for airplanes and some cars. |
Halogens | Elements in the seventh column of the periodic table such as fluorine and chlorine, that show a special tendency to form compounds with alkali and alkaline earth metals. |
Sodium chloride | A chemical name for ordinary table salt; formula is NaCI. |
Flurine | A gaseous nonmetal and halogen with many important uses. |
Chlorine | A gaseous nonmetal that is the most widely used halogen. |
Bromine | A brown halogen that is liquid at ordinary room temperatures an pressures; used as an ingredient in photographic film. |
Iodine | A nonmetal and halogen that is a purple solid at room temperature. |
What does iodine do when heated? | It sublimes. that is, instead of melting, the crystals turn directly into gas. |
Neon | An element and noble gas that is commonly used in "neon signs." |
Noble gasses | The elements in the last column of the periodic table, such as helium and argon; they do not combine with anything else except under unusual circumstances. |
Helium | A noble gas that replaced hydrogen as the gas with which to fill balloons because it is nonreactive. |
Argon | The most plentiful of the noble gases; commonly used as a filler in incandescent light bulbs |
Molecule | A tiny group of two or more atoms that are bonded tightly together. |
Mixtures | Two substances mixed together, but not bonded together, like compounds are. |
Crystal | A geometric arrangement of atoms. |
Molecular compounds | A compound composed of individual molecules. |
Ionic compound | A compound composed of charged atoms or groups of atoms. |
Diamond | The hardest of all known substances. |
In order to separate a mixture, you must find a method that affects the substances in the mixture ____________. | Differently |
Chemical reaction | A process in which atoms of elements or compounds are rearranged to form new substances. |
Combustion | Combustion occurs whenever a substance reacts rapidly with oxygen. |
Robert Boyle | A pioneer of modern chemistry responsible for discovering Boyle's law. (This law explains what happens to the volume of gas when its pressure changes.) |
Formulas | Describes the composition of a molecule. |