Periodic Table and atomic structue Flashcards
Define a pure substance
A substance that cannot be seperated into a different substance by physical means
Define mixture
A combination of two or more pure sustances that can be seperated eaisly by physical means - they are not chemically bonded
Define an atom
An atom is the smallest unit of an element, consisting of a dense nucleus of protons and neutrons surrounded by a cloud of electrons.
What is a molecule
2 or more atoms held togethro by chemical bonds, can contain dif elements eg h2o
What is a compund
2 dif elements joined togethor by chemical bonds
Whtas an element
An element is a pure substance made up of only one type of atom
Where are the protons found
In the nucleus and they are positively charged
Where are the newtrons found
in the nuclues and the are neutral
Where are the electrons found
in the shells and they are negatively charged
Opposites …. Likes
Opposites attract like repel
What is the structure of an electron shell diagram
Protons and Newtrons in the nuclues, then elcetrons on the shells,
2 than 8.
How do we use the periodic table to find the amount of subnatomic particles in a atom?
You minus the mass number - hte atomic number to find the number of electrons
The atomic number AKA the one at the bottom is the number of protons and it never ever changes.
What is the chemical symbol
The letter infront
Explain why internationally used symbolsa are used for common elements
Internatiinally recognized symblos are used for elements to create a universally understood language in science, this ensures clear comminucation and chamical formulas and experiments.
Which area of the table is metal
everywhere but top left
What area of the periodic table is non metal
the top left corner
What is teh democritus model
A solid ball model as its none as
Suggests that all atoms are small hard invisble idestructable particles made of a single material formed into different shapes and sizes
What is teh plum pudding model/tehroy
JJ tomphson suggests that atoms mostly consisted of positively charged particles and with negatively charged particles located throughout the positive material
Poistive dough, negative plums
What did Ernest Rutherford suggest?
He did a goldfoil experiment and suggested that an atom contains a small core aka a nucleuas that contains the most mass this nucleus is made up of protons which have a positive charge and that the protons are surrounded by negatively charged electrons but most of the atom is actually empty space
What is the gold foil experiment
Rutherford and his team shot alpha particels (positively chraged) at a strip of gold foil and expected them to go straight through it though this did not happen as some of them we’re replled and sent it flying directions as they hit the positive prontons in the nucleus
What is the planetary model
Neils Bohr basically suggested that electrons travel around the nucleus of an atom in orbits or paths, and aditionally can jump from path to path depending on thier energy level.
Can electrons jump from shelf to shelf?
Erwin Schrodinger further explained the nature of electrons in an atom by stating that the exact location of an electron cannot be stated;
therefore, it is more accurate to view the electrons in regions called electron clouds;
electron clouds are places where the electrons are likely to be found
What did James Chadwich
Define a chemical change
A chemical change is a change in which a new substance is formed and cannot be reversed by phsical means. (easily)
Define a physical change
A physical change is a change in the apperance of a substance without a new supstance being fromed anf can be reversed easily by physical means.
What are some every day examples of a chemical cahnge
some evryday examples of chemical changes are
. cooking food
- bruning wood or paper
Lighting a match
Souring milk
What are some evryday examples of physical changes
ice melting to water
Water boiling
Chopping veggies
Salt water
Tearing paper
Compare physical and chemical change in terms of arrangment of particles and reviseiblitiy in the process
Similarity: Both partices in a chemical and physical change move.
Differences: In an physical cahnge the partive groups inside a substance seperate but each particel group remains untouched, in other words no bonds between atoms of a moslecule break or make new ones
Verses a chemical change
Where old bonds between atoms are broken and new bonds are formed.
signs that a chemical chnage occured
A new substance is formed
A change in colour
Release of gas like co2 or bubbles
Releas of heat light and sound
signs that a physical chnage occured
A change in state
A change in shape of size
Texture xhange
Reversibility
Investigate the reversibility of a chemical change
MOst chemical changes are irreversable or only reversiable under certian conditions. An example of an irreversable change is burning paper as you are left with ash co2 and water vapour - the old bonds between atoms are broken and new ones are formed.
Though a battery which is an example of a chemical change can be recharged
Investigate the reversibility of a physical change
Almost alll physical changes can be reveresed as they do not undergoe making any new substance or changing particle groups in teh cell/no bonds between atoms are broken
Everyday examples of reversing physical changes incule:
Melting/freezing
Evarporatoin/condesation
crystilation
Streching elastic
S - G
sumblimation
G-s
deposition
Photosynthesis word equation
Word equations: water + co2 +light energy = water + carbon dioxide + energy
photosynthesis chemical equation
6C02 + 6H20 + light energy = C6H1206 + 602
Importance of photosynthesis
It produces oxygen which is fundimental for the human race to survive, it also is the energy to fuel plants and as plants are at the bottom of the food chain we would not be able to survive without them , photosynthesis/plants also take in Co2 which controls the plantes amount of carbon emmisions the green house effect and global warming.
Aerobic respiration word equation
Glucose + oxygen = Water + carbon dioxide + energy
Aerobic respiration chemical equation
C6H12O6 + 6O2 = 6Co2 + 6H20 + energy
Why is anerobic respiration important
It’s important as it allows the humans and plants to release energy from food/ photosynthesis. It gives us energy, to excercise, energy production, cell health and we need it to survive.
Rusting word equation
Iron + oxygen + water = iron oxide
Rusting chemical equation
4Fe+3O2+6h20 = 4Fe (OH) 3
Why is rusting important
It impacts the duriability and safety of iron and steel structures. UNderstanding this helps is develop portective measures like coating alloy
Combustion word equation
Fuel + Oxygen = carbon dioxide + water
Combustion chemical equation ( fuel example as methane )
CH4 + 2O2 = Co2 + 2H2O + enrgy
why is combustion important
It’s important as we use it for evryday life such as cooking, comestic heatin g, power plants and even fireworks
construct a definition of energy
The ability to do work
Define kenetic energy
Kinetic energy os energy an object posseses due to its motion
Define Potential energy
Potential energy is energy stored in an boject due to its rellative position in a system or due to its chemical or nuclear bonds
What are 5 types of kinteic energy
Heat energy
Light energy
Sound energy
Kinetic kinetic
Eletrical
What are 4 types of potential energy
Gravitational
Elastic
Nuclear
Chemicalq
What is the law of conservation
Energy cannot be created or destroyed but it can be changes from one form to another
Define open and closed systems
Open and closed systems describe how a system interactes with its envimorment They effect how stystems behace and how energy and matter are conserved of transfered.
define an energy transfer
Is the flow of energy fromm on eobject or place to another and the energy may change forms
Define an energy transformation
Is the converstion of one form of energy into another form of energy
Whats one similarity between energy transfers and energy transformations
They both include the movement of energy and energy interaction with systems
