SCIENCE - 1.4 Molecules: (EVERYTHING)
protons; neutrons; mass; 1; not; mass; tiny; decimal; isotopes
*Atomic Mass* Atomic mass is the mass of the ___ and the ___ in an atom. Every proton and neutron has a ___ of ___ AMU. Electrons do ___ count towards the ___ because they are___. The mass can be shown with a ___ because it is an average mass of the ___ of that element.
atomic number; protons; nucleus; neutral; protons; electrons; electrons
*Atomic Number* Every element has a unique ___ ___. It indicates the total number of ___ in the ___ of the atom. Normal atoms are electrically ___, same number of ___ as ___. So it is also the number of ___.
negatively; electron; levels; 1/1850; much; atom
*Electron* ___ charged particles in the ___ shells or ___. The mass of an electron is ___ than that of a proton, so it does not add ___ mass to the ___.
old; languages; chlorine; yellowish green; elements; approved
*Element Name* Every element has a unique name. Many element names are very ___ and are based on other ___. ___ is named after "khloros," the Greek word for "___ ___." Newly discovered ___ are named by the discoverer, but must be ___ by an international committee.
neutral; nucleus; charge; 1; hydrogen; not; nucleus
*Neutron* ___ particles in the ___ of the atom. They have no ___ and have a mass of ___ AMU. ___ is the only element that does ___ have at least one neutron in its ___.
positively; nucleus; 1; element; 1; 2
*Protons* ___ charged particles in the ___ that have a mass of ___ AMU. The number of protons determines the ___ of an atom. For example, hydrogen has ___ and helium has ___.
abbreviated; symbol; 2; capitalized; lower cased; Fe; iron
*Symbol* Every element is ___ using a ___ of 1 or ___ letters. The first letter is always ___ and if there is a second letter is is ___ ___. Some are based on other languages. For example, the symbol ___ is ___ form the Latin "ferrium."
chemical formula
A ___ ___ uses element symbols and numbers to show the proportion of each atom in the molecule.
atom
A molecule is made of more than one ___ bonded together.
broken down; chemical; atoms; protons; nucleus
A substance that cannot be ___ ___ into simpler substances by ___ means. An element is composed of ___ that have the same number of ___ in their ___.
matter; atoms; subatomic; protons; neutrons; electrons
All ___ is made of tiny particles called ___. Atoms are made of even smaller ___ particles called ___, ___, and ___.
atoms; protons
An element is a collection of ___ that all have the same number of ___.
fill; empty
Atoms are always trying to "___" or "___" their valence level.
empty; protons; neutrons
Atoms are mostly ___ space. The mass comes from the ___ and ___ in the nucleus!
At room temperature, water is a liquid that you may drink, bathe in, or use for cooking. It is a pure substance with its own characteristic properties, such as a boiling point and density. Water is a stable compound that reacts slowly with most substances and puts out most fires. At room temperature, both oxygen and hydrogen are gases with much lower densities than water at extremely low boiling points. Unlike water, they are considered highly reactive. Hydrogen, in the presence of oxygen and some other compounds is an explosive gas and should be handled with great care. Oxygen is also a reactive gas. Many properties of water are, therefore, quite different from the properties of hydrogen and oxygen.
Compare water to the two elements that make it up.
the smallest unit of an element that has the properties of that element
Define atoms.
tiny charged particles that surround the dense core of an atom
Define electrons.
electron cloud
Electrons are arranged in atoms in what's called an "___ ___."
atoms; protons; neutron; electron; molecules
Elements are made of ___, which have properties based on the number of ___, ___, and ___ in them. Atoms combine in certain proportions to form ___.
two; eight; eighteen
Energy levels have different numbers of atoms on each. The first level has ___ atoms. The second level has ___ atoms. The third level has ___ atoms.
Each of these shells can only hold a limited number of electrons. THe farther away the shell is from the nucleus, the more electrons it can hold. The innermost shell, located closest to the nucleus, can only hold two electrons. The cect shell can hold 8, then the next can hold 18.
Explain how electrons are arranged in shells.
If an atom loses an electron, it has a positive charge. If an atom gains an electron, it has a negative charge
Explain how losing or gaining an electron can affect the charge of an atom.
The outermost shell is called the valence, and electrons located in this shell are called valence electrons.
Explain the outermost shell.
If an atom with only one valence electron can transfer it to another atom that can hold an electron, it will. Sometimes atoms will share electrons to get the number they need.
Explain what atoms will do to try to become more stable.
the two ions are attracted to each other by their opposite charges
Explain what happens when a negatively charged ion and a positively charged ion form a compound.
Oxygen has a total of eight electrons, with two located in its inner shell and six in the next shell. The easiest way for oxygen to fill its outer shell is to gain two electrons. Hydrogen has only one electron, and this electron lies in the first shell. What happens when it meets up with an oxygen atom? If it meets up with an oxygen atom, a hydrogen atom shares its electron. When two hydrogen atoms share electrons with one oxygen atom, water forms. This sharing enables each of the hydrogen atoms to have two electrons in its outer orbit and the oxygen to have eight. Both atoms are "content" with this sharing arrangement.
Explain why water forms from hydrogen and oxygen.
a combination of hydrogen and oxygen
Explain why water is an example of different elements bonding.
3
How many neutrons are in a lithium atom?
coefficient
In the formula 4H₂O, what does the "4" stand for?
hydrogen
In the formula 4H₂O, what does the "H" stand for?
oxygen
In the formula 4H₂O, what does the "O" stand for?
subscript
In the formula 4H₂O, what does the "₂" stand for?
gives away
Ionic bonds form when an atom ___ ___ an electron to another atom.
They are usually solids at room temperature and atmospheric pressure. They have high melting and boiling points. They can conduct electricity when dissolved in liquids or melted, but not in solid form. Ionic compounds are usually more easily broken down into their separate elements than molecular compounds.
List three properties of ionic compounds.
mass; weight; space
Matter is anything that has ___ (or ___) and takes up ___.
they either completely gain or completely lose an electron or electrons
Other than covalent bonds, how can some compounds consist of more than one atom?
levels
The electron cloud has different energy ___.
valence
The electrons on the outermost shell are called ___ electrons.
two; chemical bond
The most common oxygen molecule contains __ oxygen atoms joined by __.
elemental; diatomic
The oxygen we breathe occurs as two atoms (an ___ molecule) of oxygen. This is also called a ___ molecule.
Atom
The smallest piece fo an element that still has the basic properties of the element; made of smaller (subatomic) particles called protons, neutrons, and electrons
ion
What are charged atoms called?
electrons that are grouped together in energy levels which exist as concentric layers around the nucleus.
What are shells?
elemental, diatomic, compound
What are the 3 types of Molecules?
covalent and ionic
What are the two different types of bonds?
a positively charged nucleus and negatively charged electrons, which move around the nucleus of an atom
What are the two major parts atoms consist of?
information of the number of valence electrons
What can you use to predict how atoms may combine with other atoms?
negative
What charge does an electron have?
atoms join, or bond, when they share electrons
What do atoms do when they bond?
O2
What do scientists use to stand for two oxygen atoms joined together to form a molecule?
solid
What do you think the cube symbol in the upper right means?
chlorine
What element's neutral atom has 17 electrons?
molecules that are made up of exactly two atoms; a molecule that has only two atoms of the same element
What is a diatomic molecule? What is a homogenous diatomic molecule?
two or more atoms joined together
What is a molecule?
molecules that consist of two or more atoms of the same element
What is an elemental molecule?
compound molecules
What is it called when different elements bond?
table salt (ionic bond)
What is sodium chloride?
ionic bond
What is the bond between ions called?
H2O
What is the chemical symbol for water?
Properties of compounds are very different from the atoms that make them up. For example- the properties of water are very different from the properties of hydrogen and oxygen alone.
What is the difference between a compound molecule and an elemental molecule?
covalent bond
What is the type of bond water makes called?
how all matter in the universe is made up of atoms of various elements, and how these atoms combine into molecules and compounds
What will you learn in Concept 1.4?
negative
When an atom GAINS an electron, it has a ___ charge.
positive
When an atom LOSES an electron, it has a ___ charge.
when their electron shells are either completely full or totally empty
When are atoms most stable?
electrons; molecule
When atoms bond, they share ___. This forms a ___.
atoms
___ are the basic building blocks of matter.
oxygen
___ only exists as a single molecule for a very short time on Earth becuase it is highly reactive.
Ionic bond
a chemical bond in which one atom *gives up* electrons (cation) to another atom that *gains* the electron (anion)
Compound molecules
a chemical combination of *two or more elements*
Pure substance
a material with a particular chemical makeup
Neutron
a neutrally (no charged) charged subatomic particle found in the nucleus of the atom
Proton
a positively charged subatomic particle found in the nucleus of the atom
Element
a pure substance that cannot be broken down into simpler substances by chemical reactions; made up of one type of atom
Electron
a subatomic particle with a negative charge found in set orbitals or energy levels called shells in the electron cloud surrounding the nucleus of the atom
Electron cloud
an area in which an electron is located; surrounds the nucleus of the atom; is mostly empty space
AMU
atomic mass unit
Covalent bond
chemical link between two atoms that *share* electrons
Modern atomic model
made up of a nucleus containing protons and neutrons; the majority of the mass of the atom is in the nucleus; electrons form an electron could in the area surrounding the nucleus and are located in shells
Element molecules
molecules that consist of two or more atoms of the same element
Atomic mass
the combined mass of all the protons and neutrons of an atom since each proton and neutron has a mass of approximately one unit (called an atomic mass unit) the atomic mass is equal to approximately the number of protons and neutrons
Chemical bonds
the forces that hold atoms together, these may be ionic, covalent, or metallic
Atomic number
the number of protons in the nucleus of an atom; atomic number determines the chemical properties of the atom
properties
the number of protons, neutrons, and electrons determines all of the ___ of that atom.
coefficient
the number that comes before a formula; tells how many of that particular molecule is used
Mass number
total number of protons and neutrons in an atom
Diatomic molecules
two atoms of the *same element* bonded together
Molecules
two or more atoms joined together