Question | Answer |
How are elements abbreviated in chemical shorthand? | by a Symbol. One or two letter. The first letter is always a capital. If there is a second letter it is always lower case. |
What is an Atom? | The basic building block of all matter. |
What is an element? | A substance that contains only one type of Atom. A pure substance. |
What are the three particles in an Atom? | Protons, Neutrons & electrons. |
What is the electrical charge of a Proton? | Positive (+) |
What is the electrical charge of a neutron? | Neutral (o) |
What is the electrical charge of an electron? | Negative (-) |
What is the nucleus of an atom? | The center. The part of the atom with the most mass. |
What particles are in the nucleus of an atom? | Protons & Neutrons. |
What is the meaning of the Atomic Number? | Atomic Number = |
What is the meaning of the Atomic Mass Number? | It is the number of protons and neutrons in an atom |
On the Periodic Table where can you find the Atomic Number? | The small number at the top of each square. |
On the Periodic Table where can you find the Atomic Mass number? | The larger number underneathe the symbol of the element |
Where are the electrons of an atom located? | Outside of the nucleus in an electron cloud. |
Which atomic particle determines the properties of an element? | Protons |
How much mass do the atomic particles have? | Protons & Neutrons contain most of the mass of the atom. The electrons are so small we cannot measure their mass. Electron mass is counted as zero. |
What is an Isotope? | Atoms which have the same number of protons but a different number of neutrons |
What is an Ion? | An atom with an electric charge. (must lose or gain electrons in order to become an ion) |
How does an atom acquire an electrical charge? | It gains or loses one or more electrons. |
How does a normal atom maintain a total neutral charge? | Equal numbers of Protons (+) and Electrons (-). |
Do we know the exact location of electrons in the electron cloud? | No. The exact location of electrons cannot be known for certain. We can only predict the approximate & probably location of the electrons in various shell energy levels, from closest to the nucleus to further and further from the nucleus. |
How do you find the number of Protons on the Periodic Table? | The number of protons is equal to the atomic number |
How do you find the Atomic Mass on the Periodic Table? | The Atomic Mass is the decimal number at the bottom of each square. |
What is a Shell Energy Level? | The approximate location of electrons in the electron cloud surrounding the atomic nucleus |
Democritus | Said that all matter is composed of "atomos" |
John Dalton | _____'s Atomic Theory (5 laws) |
Sir J. J. Thomson | Discovered electrons, proposed "plum-pudding atom" (electrons embedded in protons) |
Robert A. Millikan | Calculated charge of electron |
Ernest Rutherford | Discovered that there is a "dense, positively charged region" in the atom |
Bohr | Said that electrons travel in concentric circular paths around the nucleus, with fixed amount of energy for each level. |
Dmitri Mendeleev | Arranged elements by properties and mass |
Two subatomic particles found in the nucleus | protons and neutrons |
Subatomic particles with a positive charge | protons |
Subatomic particle(s)identified by the atomic number for a neutral atom | proton or electrons |
Subatomic particles with a negative charge | electrons |
Decimal number in the periodic table square | atomic mass |
Visually shows the number of valence electrons as dots around the chemical symbol of an element | Lewis Dot diagram(s) |
whole number in the periodic table square | atomic number |
building blocks of matter | atom |
found inside the nucleus, have a positve charge, and a mass of 1 amu | protons |
type of matter composed of only one type of atom | element |
type of matter where two or more elements are chemically bonded together | compound |
Only metal touching the metalloid staircase | aluminum |
Name of elements in group 2 | alkaline earth metals |
Elements with similar chemical properties are found in the same.... on the periodic table. | group |
only metal in liquid state at room temperature | mercury |
maximum number of electrons held by the second Period | eight |
an atom with a change in electrons but constant proton count | ion |
an atom with the same proton count but a change in mass due to a change in neutron count | isotope |
Elements in group 17 | halogens |
subatomic particle count found by subtracting the mass number and atomic number | neutrons |
electrons found in the last or outermost shell | valence electrons |
atomic number represents this particle in a NEUTRAL atom | proton |
small, dense core of the atom | nucleus |
Elements in group 18 | noble gases |
Maximum number of electrons found in the third shell | eighteen |
subatomic particles with a mass of 1 amu and no charge | neutrons |
rounded version of the atomic mass;sum of protons and neutrons for one isotope | mass number |
Maximum number of electrons in the shell closest to the nucleus | two |
Elements in Group 1; except hydrogen | Alkali metals |
Chemically inert or unreactive elements because they have a complete valence shell | noble gases |
elements found in groups 3 through 12 | transition metals |
smallest form of matter | atom |
Most active non-metal element | fluorine |
Most active metal element | francium |
only non-metal liquid at room temperature | bromine |
Subatomic particle with a negative charge and very low mass | electron |
vertical columns of the periodic table | groups or families |
horizontal rows of the periodic table | periods |
Identifies the valence electron count for an element except the transition metals | group number |
only non metal found on the left side of periodic table | Hydrogen |
proton | a positively charged particle |
neutron | an uncharged particle |
nucleus | the combination of protons and neutrons at the center of an atom. has a positive charge because of protons |
electrons | negatively charged particles that move around outside the nucleus |
atomic number | the number of protons in the nucleus of an atom |
atomic mass number | the total number of protons and neutrons in an atom's nucleus |
isotope | an atom of one element that has a different number of neutrons than another atom of the same element |
ion | an atom or group of atoms that has a positive or negative electric charge |
Material | particular kind of matter that has different properties that are used to characterize it |
Physical Property | is a characteristic that can be observed from a material without changing its chemical identity |
Physical Change | is a change in the form of matter but not in its chemical identity. All bonds remain intact. The same molecules are present. Temporary. |
Chemical Property | is a characteristic of a material that involves, or results in a chemical change. "ability, reactivity, or potential" |
Chemical Change | involves bond breaking and bond formation to give new products by means of a chemical reaction. Is a change in which one or more kinds of matter are transformed into one or more new kinds of matter. It yields new matter and new molecules. Permanent |
Three classifications of matter | elements, compounds, and mixtures |
Elements | are pure substances that cannot be broken down (decomposed) into simpler substances by chemical reactions. Have one kind of atom. |
Compounds | a pure substance made up of two or more elements in a fixed proportion by weight. Has two or more elements that have been chemically combined. |
Law of Constant Composition "Definite Proportions" | a pure compound, whatever its source, always contains definite, or constant proportions of the elements by mass |
Matter | any particular kind of material. Matter is either a pure substance or a mixture of pure substances |
Pure Substance | is a material that cannot be separates into different materials by any physical process. |
Pure substance | is a single chemical with definite physical properties |
Mixture | is a material that can be separated by physical processes into two or more substances. It contains two or more pure substances that are not chemically combined |
Two types of mixtures | Homogeneous and Heterogeneous |
Homogeneous | mixture is uniform in its properties throughout. Density and other physical properties are the same at every point in this mixture. Ex- a solution |
Heterogeneous | mixture that consists of physically distant parts with different properties. occurs when components of mixture do not mix well |