Chemistry Flashcards

Question

Noble Gasses?

Answer 1

Group 18 ■ Have full valence shells ■ Are very stable ■ Do not react at all so are referred to as inert. ■ Glow under particular conditions

Answer 2

Group 17 non-metals ■ Have all their valence electrons except one ■ Highly reactive ■ They want to gain that extra valence electron ■ Fluorine is most reactive

Answer 3

The atoms are held together by the electrostatic attraction between the positive nucleus and the negative electrons. ■ This force of attraction is called a covalent bond. ■ Only valence electrons participate in covalent bonding. The inner shell electrons stay around their own atom. ■ Covalent bonds are very strong

Answer 4

Have 1, 2, or 3 valence electrons ■ So valence shells are at less than half full ■ “Want” to get rid of their valence electrons ■ This makes the next inner shell the valence shell, and it’s already full ■ Atoms that have lost or gained electrons are called ions

Answer 5

Non-metals have 4, 5, 6, 7, or 8 valence electrons ■ So valence shells are at least half full ■ ”Want” to complete their valence shells

Answer 6

Positive ions are called cations – Have LOST electrons – Have more protons than electrons – Tend to be metals – Have the same name as the metal

Answer 7

Negative ions are called anions – Have GAINED electrons – Have more electrons than protons – Tend to be non-metals – Name ends in -ide

Answer 8

exchanges in chemical reactions

Answer 9

Once the ions are formed, the positive ions are strongly attracted to the negative ions ■ This attraction is called an ionic bond ■ Ionic compounds are made of ions stuck together in massive lattices ■ Ionic bonds are strong but fragile

Answer 10

Transition metals will often form more than one ion due to their complex electron configuration ■ Use roman numerals to show which ion is used – Iron (II) oxide = FeO – Iron (III) oxide = Fe2O3

Answer 11

A group of atoms that behaves as a single unit with a specific charge ■ Made up of different atoms in a fixed ratios

Answer 12

An ionic formula is the chemical symbol for the ionic compound – sodium chloride NaCl – magnesium fluoride MgF2 ■ Some rules: – The cation is always first, the anion second – Total positive charges must equal total negative charges – Use subscripts to show the numbers of each ion – If you have more than one polyatomic ion, put it in brackets

Answer 13

Metals are usually described as monoatomic elements, so can be written as a single chemical symbol – silver = Ag – magnesium = Mg ■ Noble gases are also monoatomic – neon = Ne – argon = Ar

Answer 14

non-metals in groups 14 – 17 do not exist on their own, described as diatomic ■ atoms of the element bond with each other to have full outer shells and be stable – oxygen = O2 – nitrogen = N2 – chlorine = Cl2

Answer 15

When more than one type of atom is bonded together, these are represented as a compound ■ Subscripts are used to show more than one atom of an element – carbon dioxide = CO2 – sodium chloride = NaCl – glucose = C6H12O6 ■ More than one polyatomic ion is shown in brackets – copper nitrate = Cu(NO3)2

Answer 16

In a chemical reaction, the mass of the reactants must equal the mass of the products.

Answer 17

How fast or slow these reactions occur

Answer 18

The six factors that affect the rate of reactions are: 1. Concentration 2. Pressure 3. Surface area 4. Agitation 5. Temperature 6. Catalysts

Answer 19

The concentration of a solution is a measure of the number of particles per unit volume. • Concentrated solution = large number of particles. • Dilute solution = small number of particles Increasing the concentration = increases the rate of reaction.

Answer 20

Pressure is the number of gaseous molecules in a given area. Pressure of gaseous molecules can be increased by: • increasing the number of particles • decreasing the volume of the container Increasing the pressure = increases the rate of reaction.

Answer 21

The surface area of a solid object is the total area of the outside surfaces of the 3D object. • Only the particles on the surface of a solid come into contact with the other reactant when they react. • Solid reactants will increase in surface area when they are cut up into smaller pieces or ground into a powder. Same volume – increased surface area. Increasing the surface area of a solid = increase in reaction rate.

Answer 22

When you increase the temperature of a reaction the rate of reaction also increases. • An increase in temperature (thermal energy) to the reaction is converted into kinetic (movement) energy  particles move at greater speeds. • Particles are more likely to successfully collide because they move at faster speed at the reaction’s activation energy.

Answer 23

A catalyst is a substance that can be added to a chemical reaction to increase the reaction rate by lowering its activation energy. • The catalyst is not a reactant nor a product of the reaction. • In the chemical reaction, the catalyst is written above the reaction arrow between the reactants and products.

Answer 24

Rate of reaction can be measured by: • The speed the reactants are used up. • The speed the products are formed.

Answer 25

= Quantity of reactant used up/time or = Quantity of Product formed/time

Chemistry Flashcards

(49 cards)