Last Science Quiz Of The Year Flashcards
(23 cards)
When electrons lose or gain electrons it changes the overall _________.
Charge
Atoms that lose ____________ become ions with a positive charge.
Valence electrons
Metal atoms, such as _____, become more stable when they lose valence electrons and form a chemical bond with a ________.
Sodium
Nonmetal
Why are atoms electrically neutral?
They have the same number of protons and electrons.
What happens when an atom gains or loses electrons?
It becomes a charged ion.
The attraction between positively and negatively charged ion in an ionic compound is an _______.
Ionic bound
A _________ is a bond formed when many metal atoms share their pooled valence electrons.
Metallic bond
A what surrounds the positive ions?
Sea of electrons
Why are metals good conductors of thermal energy and electricity?
Because the valence electrons can move from ion to ion.
What makes metal malleable?
Metal ions can slide past one another in the electron sea and move to a new position.
A _________ is a substance made up of two or more different elements.
Compound
What are compounds?
Chemical combinations of different types of atoms.
What do chemical bonds do?
They join atoms together.
A ___________ is a chemical bond formed when two atoms share on or more pairs of valence electrons.
Covalent bond
A computed formed from many covalent bonds is called a what?
Covalent compound
Atoms with less than 8 valence electrons become chemically stable by forming a what?
Chemical bond
A single covalent bond exists when two atoms share _____ pair of electrons.
One
A double covalent bond exists when two atoms share _____ pairs of electrons.
Two
A triple covalent bond exists when two atoms share ______ pairs of electrons.
Three
What are some properties of covalent compounds?
Low boiling and melting points, gases, liquids, or solids at room temperature, they are also poor conductors of electricity and thermal energy.
A __________ is a group of atoms held together by covalent bonding that acts as an independent unit.
Molecule
A molecule that has a partial positive end and a partial negative end because of unequal sharing of electrons is a ___________.
Polar molecule
An ____ is an atom that is no longer electrically neutral because it has lost or gained valence electrons.
Ion