Chemistry Revision Flashcards
What are the characteristics of an Acid?
- are corrosive
- have a sour taste
- Ph scale of less than 7
- Reacts with a metal to form hydrogen gas.
- Turns blue litmus indicator red.
What are the characteristics of a Base?
- Have a bitter taste
- Feels soapy
- Some are corrosive
- Can be dissolved in water
- can be called alkalis
- Ph scale of more than 7
What is the Ph scale?
The Ph scale is a scale between 1-14 that tells you how acidic or basic a substance is
How do you identify substances on the Ph scale?
- Acids have a Ph of less than 7
- Bases have a Ph or more than 7
- Neutral solutions have a Ph of 7
What are Atoms made up of?
Particles such as:
- Protons (p+)
- Neutrons (n)
- Electrons (e-)
How much heavier are p+ and n than e-?
1800x heavier (electrons are the lightest particles)
What is located in the Centre of the atom?
p+ and n, in the nucleus
What spins around the nucleus?
e-, in the electron shell
What is the difference between an Atom and an Ion?
- Atoms have no charge (p+ are equal to e-)
- Ions develop charges either positive or negative from losing or gaining electrons
How do you figure out the protons, neutrons and electrons in an element?
On the periodic table:
- the mass number, that is on top of the symbol of the element is the p+ and e-
- The neutrons are calculated by the mass number minus the atomic number
What is an element?
An element is a pure substance made up of only one type of atom. (gold, oxygen)
What is a compound?
Compounds are pure substances made up of two or more different types of atoms
What is a mixture?
Mixtures are made up of different elements or compounds that aren’t chemically bonded and can have different ratios (coke)
What is an Isotope?
Isotopes are versions of the same element, but with different numbers of neutrons
What is the electron shell configuration max
2,8,8
What is a valency?
The valency of an atom is the number of electrons on the last shell of the electron shell.
What are the types particles
- Alpha
- Beta
- Gamma
What are the characteristics of an Alpha particle?
- positively charged
- cause serious injury if inhaled, eaten or injected
- contains helium nuclei that have two p+ and n
What are the characteristics of a Beta particle?
- same size and mass as electrons
- can have positive or negative electric charge
- can penetrate and damage skin
What are the characteristics of Gamma rays?
- not particles
- high energy electromagnetic radiation produced during nuclear reaction
- no mass
- can travel at the speed of light
What do Bases and acids have?
- Bases = OH+
- Acid = H+
What is an exothermic reaction?
Exothermic reactions produce heat or light (sources of energy)
ex. fire
What is an endothermic reaction?
An endothermic reaction absorbs sources of energy.
ex. Melting ice
What are the types of reactions?
- Combustion
- Combination
- Decomposition
