Chapter 2 - Structure and Bonding Flashcards
What is a compound?
A compound contains two or more elements which are chemically combined
what are the different properties of an element
Melting/Boiling point
Density
Color
What type of metals are in group 1?
Alkali Metals
What type of metals are in group 2?
Alkali earth metals
What type of metals are in the middle of the P.T?
Transition metals
What type of metals are partially in groups 3,4,5,6,7?
Halogens
What elements are in group 0?
Noble Gases
What is a molecule?
A grouping of two or more atoms bonded together
how do you calculate mass numbers?
No. of protons + No. of neutrons
what does the number of electrons in the outermost shell show?
Which way the element reacts
What is an isotope?
atoms of the same element but with a different amount of neutrons. they can also have different physical properties.
What is ionic bonding?
Transferring electrons from a Metal to a Non-Metal to form positive metal ions and negative non-metal ions.
Describe a giant ionic structure
Ionic compounds are held together by strong electrostatic forces of attraction between oppositely charged ions. These forces act in all directions in the lattice.
what are some properties of ionic substances?
These compounds have high melting/boiling points because of the large amounts of energy needed to break the many strong electrostatic forces of attraction between oppositely charged ions in the giant
structure.
Do not conduct electricity when solid because the ions are fixed in place. When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move and so the charge can flow.
What is Covalent Bonding?
When atoms share pairs of electrons, they form covalent bonds. Covalent bonds between atoms are strong.
Covalent bonding occurs in non-metallic
elements and in compounds of non-metals.
Describe metallic bonding
Metals consist of giant structures of atoms arranged in a regular pattern. The electrons in the outer shell of metal
atoms are delocalised. The sharing of delocalised electrons gives rise to strong metallic bonds.
What are the properties of metals?
Strong metallic bonding means that most metals have high melting and boiling points, because lots of energy is needed to
break the strong metallic bonds between the positive ions and delocalised electrons.
Metals are good conductors of electricity because the
delocalised electrons carry electrical charge through the metal. Metals are good conductors of thermal
energy because thermal energy is transferred by the delocalised electrons through the structure.
What is an alloy?
A metal made by combining two or more metallic elements. different sizes of atoms disrupt metals structure making it unable to slide over each other making the metal harder than pure metal.
