Physical Science Booklet Flashcards
What is a scientific model?
A model is an representation of an idea, an object or even a process or a system that is used to describe abs explain something that cannot be experienced directly
What is all matter made up of?
All matter is made up of tiny or ticked called atoms
What is an atom?
An atom is the smallest part of an element that can exist on its own. Atoms in an element cannot be broken down into anything simpler by physical or chemical means
What is the central region of an atom called?
The central region of the atom is called the nucleus
What is protons and neutrons collectively called?
Nucleons
What makes up almost most of the mass of an atom?
The nucleus makes up almost all of the mass of an atom
Can protons move?
Protons cannot move
What is the nucleus surrounded by?
The nucleus is surrounded by a cloud of negatively charger particles called electrons. Spins in orbit around the nucleus
What makes up the volume of an atom?
Electrons
What is volume?
How much space it takes up
What is the charge of a proton? Where is it found?
Positive charge found in the nucleus
What is the charge of a neutron? Where is it found?
Have a neutral charge found in the nucleus
What is the charge of a electron? Where is it found?
A negative charge found orbiting the nucleus
Why are atoms always neutral?
The number of protons equal the number of electrons. Means that the number of positive charges is equal to the number of negative charges
What is an ion?
Adding or removing electrons will result the atom to be charged. A chafed atom is an ion. The atom is no longer neutral but stable. It does not changed the identity of an atom.
How does an ion become negatively charged?
If it gains electrons
What are negative ions called?
Anions
How does an ion become positively charged?
it loses electrons
What are positive ions called?
Cations
What usually forms cations?
Metal atoms and elements
What are isotopes?
Isotopes are atoms with the same number of protons but different number of neutrons. Therefore different mass.
What gives an atom it’s identity?
Protons
What is an element?
An element is a pure substance made up of one type of atom and that cannot be broken down into simpler substances
What is the periodic table?
A grid that arranges all of the elements we know
How many events are on the periodic table?
Currently 118 elements
What indicates a new element?
A capital letter
What is the atomic number represented by?
Z
What is atomic mass represented by?
A
What does the atomic number tell us?
Tells us the number of protons and electrons present in the nucleus of an atom. there are a number of them
What does the atomic mass tell us?
Tells us the total number of nucleons in the nucleus
How do we calculate number of neutrons?
Number of neutrons = atomic mass (A) - atomic number (Z) alphabetical order
What happens if there is a decimal point in the bohr model?
When calculating we keep the decimal point and round it off at the end
What are the vertical columns called?
Groups
How many groups are there?
18 groups
What are the horizontal rows called?
Periods
How many periods are there?
7
What is group 1 called?
Alkali metals
What is group 2 called?
Alkali earth metals
What is group 17 called?
Halogens
What is group 18 called?
Noble gases or inert gases
How are elements classified?
Elements are classified as metals, non-metals, and semi-metals (metalloids)
What does metalloids form on the periodic table?
The metalloids form a staircase which divided the periodic table
Where are metals found?
Metals are found on the left of the staircase. Hydrogen is an exception
Where are non-metals found on the periodic table?
On the left side of the staircase
What is electrical conductivity?
The ability of a substance to allow a charge to flow through it
What is heat conductivity?
The ability of a substance to transfer heat
What is metallic lustre or dullnes?
Describes how shiny or dull a substance is
What is malleable?
The ability of a substance to be hammered and shaped without breaking
What is ductile?
The ability of a substance to be drawn into thin threads.
What does strong or brittle mean?
Describes how easy a substance breaks
What is a diatomic element?
Elements which naturally occur as molecules made up of two identical atoms chemically bonded. They must be identical
Name the diatomic elements
Hydrogen Nitrogen Fluorine Oxygen Iodine Chlorine Bromine
have no fear of ice cold bear
What is a pure substance?
Cannot be separated by chemical means. Split into two groups. Elements and compounds
What is an element?
A pure substance made up of tiny particles called atoms. Pure because it is made up of one type of atom only
What is a compound?
Consists of two or more different elects chemicals bonded together in a fixed portion
What is an impure substance/mixture?
The result of a combination of two or more substances not reacted chemically. Can be separated by physical processes
Why is it called impure substance?
Their portion may vary
What is a heterogenous mixture?
The component parts can be distinguished
What is a homogenous mixture?
Component parts cannot be distinguished
What is diffusion?
The movement of particles from an area of high concentration to one of low concentration, until the particles are evenly distributed compounds
What does a chemical formula tell us?
Tells us the ratio of the atoms within a specific compound
What is a binary compound?
A binary compound if one in which there are atoms from two different elects present
What is valency?
The number of bonds an atom of a particular element can make when bonding with another atom
How do we name a binary compound with a metal + non-metal (ionic)
Name of the first element first Second element must end with ide
How do we name a binary compound with a non-metal + non-metal (molecule)
We add prefixed and second element ends in ide 1 - mono 2 - di 3 - tri 4 - tetra 5 - penta 6 - hexa
What is a particle diagram?
A way of representing molecules and compounds
What is a chemical reaction?
A process that occurs when two substances react to form a new substance, which have different chemical properties than the original reactants
What is a reactant?
Original substance. can have more than 2. Present at the start of a chemical reaction
What is a product?
Substances present at the end of a chemical reaction. Can have more than one product.
What indicates a chemical reaction?
An arrow not an =
What are the three chemical reaction equations?
Word equation, particle diagram and chemical equation
What is a chemical equation?
Chemical reactants and products. A symbolic representation of a chemical reactions
What is the law of conservation of mass?
The total mass of substances taking part in a chemical reaction is conserved during the reaction. Meaning that mass cannot be created or destroyed
Why should the reactants and products be balanced?
It must be balanced because if the law of conservation of mass
How do we balance chemical reactions?
By using subscripts and coefficients
What are subscripts?
Indicates how many atoms of a specific element are present in a compound
What is a coefficient?
Indicates how many molecules of each reactant or product is present
What is the particle model of matter also known as?
It is also known as kinetic molecular theory.
What is the particle model of matter?
Scientific model used to explain that all matter is made up of particles (atoms and molecules) and used to explain the properties and behavior of matter
What does the particle model state?
- All matter is made up of tiny particles called atoms.
- The particles are always moving. Move faster when heated and slower when they lose heat.
- The particles have empty spaces between them. Nothing exists in the spaces.
- They are forces of attraction between them. Force of attraction is strong when particles are close. Force of attraction is weak when patricles are far away
What are solids?
Solids are made up of particles that are very close together. Solids are held together by strong forces of attraction. Solids cannot be compressed. Particles do not flow but only vibrate. Solids have a fixed shape, fix volume and high density
What is the kinetic energy of solids?
Solids have a low kinetic energy.
What are liquids?
Liquid are made up of particles that are closer together than gas. Forces of attraction are strong but weaker thans forces in solids. Particles are able to slide over each other. Liquids cannot be compressed. Liquids have a fixed volume but not a fixed shape and lower density than solids.
What is the kinetic energy of liquids?
Particles move easily as a kinetic energy between the particles are greater than solid but weaker than in gases.
What are gases?
Gas is all made up of particles that a while spread out. No forces of attraction. Gases are easy to compress. There is no fixed volume, no fixed shape and lower density than in liquid. When gas is a heated it expands. Gases contain millions of fast moving particles. They bump and bounce off of each other.
What is the kinetic energy of gases?
Particles in gas move easily as they have a high kinetic energy
What is pressure in gas?
The force of the particles bumping against the sides of a container is called gas pressure.
What were the number of collisions in gas pressure depend on?
The number of collisions will depend on the number of gas particles. The more particles means more collisions and more collisions means higher pressure
How is gas pressure measured?
A tyre pressure gauge is used. It is designed to measure air pressure in a tyre. The end of a gauge is pressed against the air valve. Air from the tyre escapes. Air particles bump against a disc inside the gauge. The force is generated by many gas molecules collisions pushes out the bar.
Does heating a gas change its pressure?
If the gas is heated the particles will move faster as they gain more energy. They will collide more often with more force and this causes an increase in pressure.
How does cooling a gas change its pressure?
If the gas is called the particles move more slowly because they have less energy. They are less collisions with less force therefore gas pressure will decrease
How does changing the volume of a gas change its pressure?
The smaller volume the particles have the less space they have to move. The gas particles will collide more often. More collisions means increased pressure. When we change the volume you are not changing the temperature.
What is physical change?
Matter changes forms but does not change the chemical identity. No new substance has been formed. Particles have exactly the same chemical structure but may look different.
Does thermal energy have to do with physical change?
Thermal energy may be added or lost if the substance changes phase
How can physical change be reversed?
Physical change may be reversed by physical means such as filtration and distillation
What is chemical change?
A chemical reaction occurs in a new product is formed. The particles of a new substance have different chemical structure from the original substance.
What does thermal energy have to do with chemical change?
When chemical bonds are broken and formed thermal energy is absorbed and released
How can chemical change be reversed?
The reaction may only be reversed through chemical reactions.
What is five signs that a chemical reaction has occurred?
- Color change
- Formation of an odor
- Large change in temperature
- Formation of a gas (bubbles)
- Formation of a precipitate (solid)
What is mass?
The mass of an object or a substance tells us how much matter it consists of. It is the amount of atoms
What happens the greater the mass of the object?
The greater the mass of an object, the more matter it contains.
Does the mass of an object change?
The mass of an object stays the same no matter where it is. Unless a piece of it is cut off
What will mass always remain?
Mass will always remain constant
How is mass measured?
It is measured in KG and grams. A triple beam balance measures mass. It is not the same as a scale
What is volume?
Volume is the amount of space that an object occupies
How is volume measured?
Volume is measured in litres and millilitres
How is volume calculated?
It is calculated by multiplying the length, width and height of an object. L times B times height
What we change of volume?
We change the distance to volume. 1000 centimetre cubed is the same as 1 L which is 1 cm³ equals to 1 mm
How do we measure volume of regular shapes?
Reggy don’t geometric shapes such as rectangular box, cube, cylinder, she can be determined by using the volume formula for the shape. Which is volume is equal to the length times with times height.
Eg, v = 4 x 2 x 3
= 24cm3
= 24 ml
How do we calculate the volume of an irregular shape?
Fine by water displacement. Volume of water sufficient to cover the object is placed in a graduated cylinder and the volume is red. The difference between the volumes is the volume of the object
eg. 26ml - 10ml
= 16ml
What is density?
A measure of how much mass of a material fit into a given volume. How tightly packed a material is. Density is the ratio of mass to volume
What is the formula of density?
D = m/v
What does the higher the density mean?
Higher mass equals higher density
What does the lower the density mean?
Lower volume equals lower density
How do we measure density?
We measure density in KG/L or G/ML
What does density determine?
Density determines whether an object will sink or float in another substance
What does it mean if the object will float?
The object will float it if it is less dense than the liquid it is placed in
What does it mean if the object will sink?
The object will sink if it is more dense
Density is a characteristic property of a substance. What does this mean?
Identity is a characteristic property of a substance which means that it does not depend on the amount of substance
What is the key to floating?
The key to floating is being light for your size – having less mass.
What does adding size to an object without adding much mass do?
Adding size to an object without adding much mass means the object will be lighter relative to its size. Meaning that the density of the overall object will decrease and more likely to float
What is the key to sinking?
The key to syncing is being heavy for your size, having more maths. Adding mast to an object without adding much size. The object will be heavier relative to size. Meaning that density of the over object will increase and be more likely to sink
What is static electricity?
Also known as electrostatics. The movement of electrons. It is the imbalance of charges in a material which is not neutral. The effects are all around us. We do not always recognise see or feel
What does the position of electrons mean?
Due to the position of electrons the electrons can either leave or enter an atom. Hence, changing the charge of a neutral atom
What happens when an atom loses electrons in static electricity?
When an atom loses electrons it gains a positive charge. They are more protons and electrons are present. There is a deficient of electrons
What does it mean when atoms gain electrons in static electricity?
When atoms gain electrons there have a negative charge. More electrons and protons are present as there is an excess of electrons
What is a neutral atom in electrostatics?
Equal number of protons and electrons hence the charge is neutral
What is the study of static electricity known as?
Electrostatics is the study of static electricity. They study the behaviour of charges in nature
How do you objects become more positively or negatively charged?
Objects become more positively or negatively charged based on the movement of electrons
What type of atom can only be moved?
Only electrons can move will be transferred
How do you object acquire a charge?
Charge through the process of friction
What is friction?
The resistance of a surface or object encounters when moving over another, and occurs when the surface of two objects around against each other
What is triboelectric charging?
The process of electron transfer as a result of two objects coming into contact with each other and then separating
What does tribo mean?
Means to rub
What does triboelectric charging result in?
It results in one object gaining electrons on its surface am becoming negatively charged. The other object is losing electrons from its service and becoming positively charged
What is the triboelectric series?
It is a list that ranks various materials according to their tendency to gain or lose electrons
What do you like charges do? What do unlike charges do?
Like charges repel. Unlike charges attract
What are objects before any electrons have been transferred?
Before any electrons have been transferred objects are electrically neutral. The number of negative and positive charges remain constant.
What happens when there are more charges?
The more charges they are the bigger the charge is
When did charges transfer more readily?
Charges transfer more readily when the air is dry
What is the type of charge caused by?
Type of charges are caused by friction which depends on kind of material being rubbed together
What is an electroscope?
An electroscope is a device used to detect the presence of a charge. It is constructed with a metal plate at the top of a metal rod with tinfoil is leaves hanging from the bottom of the rod
What is the charge put on?
The child has put on a disk/At the top it spreads down to the plate and the leaves. Charges of leave and plates are the same. Similar charges repel each other. Delete rises away from the plate. The bigger the charge the more the leaf rises.
What must you do to make the leaf fall again?
For the leaf to fall again you must touch the disc or cap. It earths the electroscope
What are the two ways an electroscope can be charged?
- Contact. A charged rod is touched on the surface of the desk. The charge is transferred to the electroscope
- Induction. A charged rod is brought close to the desk. The electroscope is earth – rod is removed
What is the Van De Graaf generator?
A machine which uses friction to generate a large buildup of electric charge on a metal dome
What is the Van de Graaf generator used for?
It is used to demonstrate the effect of an electrostatic charge
How is the Van De Graff generator discharge?
It can be discharged by bringing another insulated metal sphere close to the dome. The electrons will jump to the dome from the metal sphere and cause a spark.
When does the generator become positively charged?
The big metal dome at the top becomes positively charged when the generator is turned on
How does the generator transfer a charge to the person who is touching it?
Transfers a charge to the person who is touching it such as the persons hair follicles receive the same charge and each individual hair repels each other
What is polarisation?
Charged objects is when charged objects attract a neutral object
What is the charged object able to do in polarisation?
The charge object is able to attract or repel the electrons depending on charge a neutral object
What happens when it is a positively charged object in polarisation?
If it is a positively charged object it attracts the electrons in the neutral object. The electrons in the neutral object moves to the side of the object closest to the charged object
What happens when it is a negatively charged object in polarisation?
When it is a negatively charged object the electrons repel each other. The electrons in the neutral object move to the side furtherest from a charge object
What happens when the object is neutral in polarisation?
A neutral object has a negative and positive side
What is electrostatic discharge?
Electrons transfer from a charge object to a neutral object. The charge object has discharged. It takes place when objects touch each other
How do electrons transfer in electrostatic discharge?
Electrons are transferred from one object to another Wayne Road closed without touching
What do you electrons move across in electrostatic discharge?
Electrons move across a gap which heats the air enough to make a glow. The glow is called a spark.
What can discharge cause in a electrostatic discharge?
Discharge can cause electrics shocks
What does earthing mean?
We must connect the charge object to the ground(earth) with electrical conductor. The electrons travel along the conductor and into the ground without harm
How do we discharge extra electrons safely?
They discharge of extra electron safely we must Earth it
Why does extra charge not have an overall affect?
Extra charge does not have an overall effect because the Earth is so large
What is electrostatics all around us?
- Lightning
- Dust clothes
- Danger of static electricity
What is lightning?
Negative charges (electrons) in the bottom of a cloud are attracted to the positive charges in the ground. This causes a bolt of lightning. Negative charges for down towards a high point where the positive charges have clusted together
What causes lightning to expand rapidly?
Lightning heats the air along the path which causes it to expand rapidly
What is thunder caused by?
is caused by rapidly expanding of a
What is current electricity?
It occurs when there is a continuous movement of electric charge in an electric circuit. It is the flow of electrons
What does static electricity study?
Static electricity Studies charges at rest. There is no movement.
What is the size of the electrical current to determine by?
The size of the electrical current is determined by how fast charges move in a circuit. Faster equals higher
What is a conductor?
Substances or materials that allow for the free movement of charges. Such as copper, silver, aluminium, gold, seawater
What are insulators?
Substances or materials that you’re not allowed charges to past two. Such as non-metals, plastic, glass, rubber, wood, cloth
What is an electric circuit?
A path along which charges can move, or through which the current can flow
What are the two things that make sure a current can exist?
- A close circuit. In other words components and conducting wire forms a close circle. There is no flow if there is no current when they are gaps there are no charges
- A source of electrical energy in the circuit. Such as a battery/cell. The battery does not create charge but it gives it energy to move
What is the conventional current?
Refers to the flow of positive charge from the positive terminal along the electrical circuit back to the negative terminal
Who is convention used by?
Convention is used by electricians and electrical engineers
What is a circuit diagram?
It is a simplified drawing news to show how different components are connected in a circuit. It forms electrical circuits
What does each component in a circuit diagram have?
Each component has a specific function and is represented by the symbol. Do you not labelled the circuit diagram
What is a cell?
The source of energy for electric charges. A long line represents the positive terminal. The short line represents the negative terminal. Two more cells connected form a battery. Positive to negative
What is a switch?
Controls the flow of the charge. Open switch present flow of charge. Close switch completes the circuit, allowing the charge to move
What is a resistor?
Slows down the flow of charges. All conductors provide resistance
What is a lightbulb?
A lightbulb is a type of resistor. Filament has high resistance and heat up to be white Hot. The electrical energy converted into heat energy and then light energy
What is a fuse?
It protects the circuit. Overheat fuse melt which create an open circuit
What is an anmeter?
It is a device used to measure the current. It always connected in series
What is a volt meter?
It is a device used to measure the potential difference. It is always connected in parallel and measures vaults
How do we connect circuit?
Components can be connected into different ways. These ways are known as series and parallel
What is a series connection?
Components are connected into end and form a single path for the charges to flow through. If one component breaks the current is unable to flow meaning that the components cannot work
What is a parallel connection?
Components are connected across from each other, forming more than one path for the charges to flow through. If one component breaks the charges have an alternative path to flow through. The circuit continues to work
How do we draw circuit diagrams?
Always use a ruler and a pencil. Do you not labelled the components. The symbols indicate what the component is
What is the effect of an electric current?
- Generate heat in a resistor
- Generate a magnetic field
- Cause a chemical reaction in a solution
What is the heating effect?
Electrons move through a resistor. As they encounter resistance and they transfer energy to the resistor itself. Energy is transferred as heat
What does the incandescent light bulb do?
Electricity flows through the filament that is made out of tungsten.
What is tungsten?
Tungsten has a high resistance and is very thin. Which offers even more resistance
What does resistance course in the heating affect?
Resistance causes energy to be transferred to the filament as heat. Heat makes the filament white hot which produces light
Is heat and temperature the same thing?
Heat and temperature or not the same thing
Define temperature
Temperature is a measure of how hot or cold something is. We measure in degrees Celsius
Define heat
Heat is the transfer of thermal energy from a hotter object to a colder object (J) Jewels
Why can the heating effect of an electric current be dangerous?
If the circuit overheats it could cause a fire. To avoid overheating circuit contain a fuse
What does a fuse contain?
Fuse content a low resistance wire made of metal with a low melting point. If the wire amounts it gets too hot.
why do we need different types of fuses?
Different circuits need different strength currents which means that we need different types of fuses
How do we choose what fuse we use?
We choose the fuse that suits the safety of the circuit. If the circuit overheat the fuse will melt and break the circuit
What happens if the fuse melts?
The circuit breaks which reduces the danger of fire and protection of electronic equipment
What is a short circuit?
A short circuit happens when another, easy apart it’s accidentally made in an electric circuit. An easier path office very little resistance to electric current. The current flows along the short circuit and doesn’t pass through the main circuit
What is the magnetic affect?
When a current passes through a wire to create a magnetic field
What is a magnetic field?
A magnetic field is a region in space in which another magnetic object will experience a force of attraction or repulsion
How can a magnetic field be seen?
It’s can be seen using iron fillings on a piece of cardboard, through which a current has passed. This creates concentric circles
What is a chemical effect?
Electric current is passed through an ionic solution. Chemical reaction may occur
What is an ionic solution?
And ionic solution is one in which an ionic solid (which consists of a metal bonded to a non-metal) is dissolved in a solvent, usually water
What happens to the solid in the ionic solution?
The solid dissolves which means it breaks up the positive and negative particles
Define electrolysis
Is the process by which ionic substances are broken down into simpler substances when an electric current is passed through them
