Chemistry And Electronics 1 Flashcards
Atomic number
Number of protons and electrons (they’re the same) listen in increasing order on the periodic table
Periods
Rows of elements, correspond to the number of shells, or different orbits of elections around the atom
Groups
Columns of elements, same number of electrons in their outermost shell
Alkali metals
Group 1, silvery metals that react strongly with water
Noble gasses
Group 0 or 18, Don’t react with other elements because outer shell is completely full
Atomic mass
The average mass listed, average because atoms could come in different sizes (isotopes)
Atomic mass unit (amu)
Each proton and neutron’s mass
Ionic compound
Example: NaCl (salt), because each chlorine atom borrows an electron from each sodium atom to form a tightly bound crystalline structure
Ion
Electrically charged atom
Covalent compound
Example: Sugar, it doesn’t ionize when dissolved in water. It shares electrons in pairs so they don’t separate as ions do.
Acid
A substance that gives up a positively charged hydrogen ion when dissolved in water. Sour.
Base
A substance that gives up a negatively charged hydroxyl ion when dissolved in water. Alkaline. Bitter
pH
0 to 14 scale indicating how basic or acidic a solution is. pH less than 7 is acidic, more than 7 is basic, 7 is neutral
Phase transition
Physical change, changing of state of matter (liquid to solid)
Reactants
In a chemical change the molecules and atoms that enter the reaction, result is the product
Electricity
All electricity from static shock to lightning is a movement of electrons
Valence shell
Outer shell of an atom, number of electrons depends on if it’s a conductor, semiconductor, or insulator
Conductor
Element that allows electrons to move freely, they have one or more mobile valence electrons per atom that are free to move from one atom to another
Insulator
Valence shell that’s more than half full. Doesn’t conduct electricity much at all, electrons tightly bound to their own shell.
Semiconductor
Exactly half-full valence shell, not a good conductor or insulator
Current
Rate of flow of electrons through a conductor
Charge
Electrical current is measured by charge flowing past unit of time
Amperes (amps)
How current is measured. Defined as one coulomb, the basic unit of electrical charge in one second.
Ammeter
Device used to measure current
Voltage
Electrical pressure, measured by volts. Voltage and current are directly proportional
Electric potential
Electrons pushed to areas of greater electric potential (high pressure) to lower electric potential. AKA electrical potential difference or electromotive force.
Voltmeter
Device that measures voltage
Resistance
Opposition to the flow of the current, measured in ohms. Measured with ohmmeter, Greek omega symbol
Conventional current
The imaginary flow of positive charge and is opposite in direction to actual electron flow
Circuits
A complete loop or path for electricity to follow.
Load
A source of resistance that converts electrical energy into some other form of energy, for example a lightbulb (electrical>light and heat)
Ohm’s Law
Voltage in colts is equal to the current in amps multiplied by the resistance in ohms.
V=IR
Series current
An electrical circuit that has only one path for current to flow. A break anywhere will stop the current. Simplest possible circuit
Parallel circuit
More common. Each load is wired in a separate path. If a path has a break or gap, the current would continue, there’d still remain a closed circuit
Series-parallel circuit
Most popular, includes on/off switch, wired in series with a number of loads that are connected in parallel
Electrical power
A term that refers to the actual rate at which energy is provided to and consumed by an electric circuit. Expressed in watts (joules per second), can be calculated by voltage x amps
P=IV
