Science: Chapter 8

Compare the charge of metal atoms and nonmetal atoms.

-Metal: since metal atoms have few electrons in their outermost energy level, the tend to give it away, therefore, forming a positive charge Nonmetal: since nonmetal atoms have a pretty full outermost level, they tend to take in electrons, therefore, forming a negative ion

How do you know if an atom will form bonds?

-by looking at a valence electron in the outermost energy level of an atom -atoms with less than 8 valence electrons will form not bonds

What are ions?

-charged particles that form when an atom loses or gains electrons -negative charges and positive charges no longer cancel out

What 2 properties allows metals to be reshaped?

-ductility: (ability to be shaped into wires) -malleability: ability to be rolled or pounded)

Describe the electron arrangement in an atom.

-first energy level: closest to the nucleus. can hold up to 2 electrons -second energy level: follows the first energy level. can hold up to eight electrons. (begin filling only after first energy level is full w/ 2 electrons) third energy level: fills w/ electrons after 2nd energy level is full. needs 8 electrons to be full

What is a chemical bond?

A chemical bond is an interaction that holds two atoms together.

What is a covalent bond? (share)

A covalent bond is when atoms share one or more pairs of electrons.

What is a molecule made up of?

A molecule is made up of two or more atoms joined in a definite ratio. (a hydrogen molecule is made up of two covalently bonded hydrogen atoms)

When happens during an ionic bond?

An atom loses an electron and the other atom gains an electron. (give take situation)

What does an electron dot diagram help you predict?

An electron dot diagram helps you predict how an atom might bond.

What is an electron dot diagram?

An electron dot diagram is a model that shows only the valence electrons in an atom.

What are the reasons why atoms in metals can be rearranged and why metals can be reshaped?

Atoms in metals can be rearranged because the electrons move freely around the metal.

What is chemical bonding? (new substances)

Chemical bonding is the joining of atoms to form new substances.

What happens to atoms when chemical bonds form?

During chemical bonds, atoms share, gain, or lose electrons.

An ionic bond forms because of the weak forces of attraction between the positive metal ions and the negative nonmetal ions. True/False

False -An ionic bond forms because of the STRONG forces of attraction between the positive metal ions and the negative nonmetal ions.

Elements are grouped based on DIFFERENT properties. True/False

False -elements are grouped based on similar properties

Atoms of which group in the periodic table give off the most energy when forming negative ions?

Group 17, the Halogens -bc they are very reactive

What are ionic bonds? (transfer)

Ionic bonds is when valence electrons are transferred from one atom to another.

Metallic bonding allows metals to do what?

It allows metals to conduct electricity.

When does an ionic bond form?

It forms when atoms pull electrons away from other atoms (atom that loses electrons=positive ion bc now has more protons than electrons)

The Atomic number tells you what?

It tells you the number of protons as well as the number of electrons in an atom.

Why can metals be reshaped/ bent without breaking?

Metals can be reshaped/bent without breaking because metallic bonds occur in many directions. -Metal can be shaped bc of the presence of metallic bonds

Notes

Molecules are basically the atom of covalent bonded compound.

... that have ... consist of particles called ...

Substances that have covalent bonds consists of particles called molecule.

Describe the substances that have covalent bonds. Give an example.

Substances that have covalent bonds tend to have low melting and boiling points and are brittle in the solid taste. (ex: oxygen has a low boiling point, that's why it is a gas at room temperature. cellulose is brittle, thats why wood breaks when bent.)

What do the electrons do in metal atoms?

The electrons keep the ions together and cancel the positive charge out of the ions.

Contrast the number of electrons for metal atoms and nonmetal atoms in an ionic bond.

The number of electrons lost by the metal atoms equals the number gained by nonmetal atoms.

Describe the properties of an element that has just gone through chemical bonding.

The properties of the new substance is different from the properties of the original element.

How are electrons organized in an atom?

They are organized in energy levels.

How is ionic bond and chemical bond similar?

They are similar because they both form so that the outermost energy level is full

How do positively charge metal ions form?

They form when metal atoms lose electrons.

Why do the outermost energy levels of metal atoms overlap?

They overlap because metal atoms are so close to one another (metal atoms are so close bc of their bonding)

Give examples of some things or elements that are held together by covalent bonds.

Things that are held together by covalent bonds are water, sugar, oxygen, and cellulose in wood.

Why do atoms of nonmetals tend to gain electrons from other atoms?

This is because their outermost energy level is almost full, therefore, they need a few more electrons to fill iy.

Describe the movement of electrons throughout a metal.

Valence electrons can move throughout the metal because metallic bonds extend throughout the metal in all directions. (electrons are not connected to any one atom.)

Describe how to draw an electron do diagram.

Write the symbol of the element, then write one dot for every valence electrons in the atom

Notes

You can think of metals as having positive metal ions that have valence electrons swimming around

What do you need to know to understand how atoms form chemical bonds?

You need to know about the electrons in an atom.

What are molecules? (group)

a group of atoms held together by chemical forces; a molecule is the smallest unit of matter that can exist by itself and retain all of a substance's chemical properties

What is a metallic bond? (for metals)

a metallic bond is a bond formed by the attraction between positively charged metal ions and the electrons around the ions.

What is a valence electron?

an electron found in the outermost energy level

What happens in a covalent bonding?

atoms bond by sharing electrons not transferring electrons like in ionic bonding

Why is an atom neutral?

bc the number of electrons equal the number of protons

How can substances be formed?

by combining atoms

How do you form negative ions?

by gaining electrons from other atoms

How do atoms bond with other atoms?

by gaining, losing, or sharing electrons

How can you determine the number of valence electrons in the periodic table?

by looking at the group numbers -Within a group or family, the atoms of each element have the same number of valence electrons

Molecules are composed of at least 2 covalently bonded atoms. What are the two atoms?

diatomic molecules

What are the simplest molecules?

diatomic molecules

What are the properties of metal? (3)

electrical conductivity, malleability, and ductility

Notes

electrons play are important role in metallic bonds (maintains the bond, keeps ions together, cancel positive charge of the ions, always moving around/between the metal ions) -positive ions in a metal are always surrounded by and attracted to electrons in the metal

Give some examples of diatomic elements.

hydrogen, oxygen, nitrogen, flourine, chlorine, bromine, iodine

How can you tell if the outermost energy level is full?

it is full if the outermost level contains 8 electrons (nonreactive if have 8 valence electrons) (reactive if have less than 8)

What does the ending "-ide" mean?

it is used for the names of the negative ions that form when atoms gain electrons

What gives metals their particular properties?

metallic bonding

What maintains the metallic bond?

the moving electrons

What determines the atom's CHEMICAL PROPERTIES?

the valence electrons

What is a negative ion?

when an ion has more electrons than protons

What is a positive ion?

when an ion has more protons than electrons

Can molecules be composed of different elements?

yes, most molecules are composed of two or more elements