unit two part four

Question 1

a chemical reaction is?

Answer 1

the process by which one or more substances(reactions) are changed into one or more new substances (products)

Question 2

What are some indicators that a chemical reaction has taken place?

Answer 2

They release or absorb energy (heat, light, sound and electricity), a release of an odor, production of gas, or the formation of a precipitate.

Question 3

What are the five different types of chemical reactions?

Answer 3

Synthesis, decomposition, single replacement, double replacement, and combustion.

Question 4

how do you recognize a synthesis reaction?

Answer 4

Two or more substances combined to form a new compound. (A+B –> AB)

Question 5

How do you recognize a decomposition reaction?

Answer 5

A single compound is changed into two or more simpler substances. (AB –> A+B) ab is a compound and a and b can be elements or compounds.

Question 6

What do decomposition reactions generally need?

Answer 6

Energy added in the form of heat, electricity, or light

Question 7

The decomposition of a substance by an electric current is called?

Answer 7

electrolysis

Question 8

how do you recognize a Single replacement reaction?

Answer 8

One element replaces a similar element in a compound. (A+B–> Ac+ Bor A+Bc–> Ba+C where ab and c are elements and bc ac and ba are compounds)

Question 9

How to recognise a double replacement reaction?

Answer 9

In an aqueous solution the ions of two compounds exchange places to for two new compounds(AB+CD AD+CB where A,B,C and D are ions and AD and CB are ionic or molecular compounds)

Question 10

One of the new compounds in a double replacement reactions?

Answer 10

solid precipitate an insoluble gas or a molecular compound (usually water) The other compound often remains dissolved in solution (precipate, gas, water)

Question 11

How to recognize a combustion reaction?

Answer 11

a substance combining with oxygen in the form of heat and light

Question 12

The products of the complete combustion of a hydrocarbon are

Answer 12

CO2 and water

Question 13

The product of the combustion of most other substances is

Answer 13

an oxide

Question 14

in a combustion reaction what is oxygen?

Answer 14

a reactant

Question 15

To predict the reaction typeand the possible products of a reaction

Answer 15

examine the reactants to determine if they are elements or compounds and how many of each type there are.

Question 16

what happens to electrons in oxidation?

Answer 16

oxidation is the loss of electrons and reduction is the gain of electrons

Question 17

Oil Rig Leo goes Ger

Answer 17

Oxidation Is Loss Reduction Is Gain, Gain of Electrons is Reduction

Question 18

oxidation and reduction…

Answer 18

must occur simultaneously and the total numbers of electrons must be balanced between the two reactions

Question 19

oxidation is the loss of electron so

Answer 19

the oxidation number of the oxidised element increases (becomes more positive) during a redox reaction

Question 19

The oxidation numbers for atoms that can vary are found

Answer 19

using those that are known and the sum total for the entire compound or polyatomic ion

Question 19

As with meatal that can exist as several different cations

Answer 19

some nonmetals have variable oxydation states

Question 19

Reduction is the is gain of so

Answer 19

the oxidation number of the reduced element decreases (becomes more negative) during a redox reaction.

Question 19

If none of the oxidation numbers of the substances in a reaction change

Answer 19

the reaction is not a redox reaction

Question 20

Many …. are redox reactions

Answer 20

synthesis, decomposition, single replacement, and combustion

Question 20

what are not redox reactions

Answer 20

double replacement reactions (including acid-base neutralization)

Question 21

The reaction equation for a redox reaction can be broken down into two

Answer 21

into its two half reduction equations

Question 22

There is a .... of isotopes with

Answer 22

Band of stability, stable proton to neutron ratio

Question 23

Raidoactive decay is

Answer 23

The spontaneous disintegration of an unstable nucleus into a slightly lighter but more stable nucleus

Question 24

Isotopes that undergo radioactive decay are called

Answer 24

radioisotopes

Question 25

An alpha particle is equilalent to

Answer 25

a helium nucleus (2 protons and 2 neutrons bound together)

Question 26

In alpha particle emmission..

Answer 26

the mass nuber and the atomic number both decrease

Question 27

Abeta particle is an electron emitted

Answer 27

from the nucleus

Question 28

in beta particle emmision

Answer 28

the mass number stays the same and the atomic number goes up

Question 29

Gamma emmision

Answer 29

high energy gamma rays are emitted by the nucleus as it changes from an excited energy level to a lower level due to the nucleus forming a more stable arrangement of particles

Question 30

what is nuclear fission

Answer 30

the splitting of a nucleus that has been made very unstable by bombarding it with neutrons

Question 31

what does nuclear fission produce

Answer 31

produces lighter, more stable (but still radioactive) nuclides while releasing great energy and more neutrons

Question 32

where does fission occur?

Answer 32

fission occurs naturally in small amounts of matter with heaver nuclei

Question 33

what it nuclear FUSION

Answer 33

the combining of nuclei of light mass into one heavier, more stable nuclide while releasing tremendous energy.

Question 34

what are the reactants and products of nuclear fusion?

Answer 34

The reactants are readily available and the products are non-radioactive nuclides. The products

Question 35

what does nuclear fusion require?

Answer 35

Requires extremely high temperatures & pressures not currently sustainable or containable