Material World Flashcards
bases have a pH of what on the pH scale?
7.1-14
neutrals have a pH of what on the pH scale
7
The charge of an atom is based on what
The number of protons and electrons it has
is the ion positive or negative if the number of protons is greater than the number of electrons
+ion
is the ion positive or negative if the number of electrons is greater than the number of protons
-ion
how does an aqueous solution conduct electricity
when a compound is added to it, The compound will separate into two separate charges when dissolved in water
what is needed for combustion
heat
fuel
oxidizing agent (usually oxygen)
what is the equation for combustion
CH4+2O2—>2H2O+CO2
what are three reactions of the carbon cycle
photosynthesis, respiration, and combustion
what is the equation for respiration
C6H12O6+6O2—>6CO2+6H2O
what is the reaction of photosynthesis
6CO2+6H2O—>C6H12O6+6O2
what are periods on the periodic table
The different rows
what’s common about each element in a period
they have same number of electrons shells
what are the groups on the periodic table
The different columns
what does each group have in common
same number of valence electrons
where are noble gases located
eighth group
where are halogens located
seventh group
where are alkaline metals located
first group
where are alkali earth metals located
Second group
which family is stable
Noble gases
which families are highly reactive
halogens and alkali metals
what does the Rutherford-Bohr atomic model show
The nucleus with protons only and electrons per shell
Protons have a _____ charge
positive
Electrons have a ______charge
negative
Neutron have _____ charge
no
objects with the same charges will _____ each other
repel
Objects with opposite charges will _____ each other
attract
what is static electricity
it’s the transfer of electrons from one body to another
what are the three ways you can conduct static electricity
friction, conduction, and induction
what is friction
two materials rubbing together and their electrons transfer from one and other
what is conduction
when two materials touch each other and the electrons transfer
what’s induction
when two materials approach each other and their electrons jump from one material to another
what is Ohm’s law
V=IR
what is a direct current
The electrons are flowing in one direction
what is an alternating current
when the electrons flow back and forth many times per second in a regular pattern
what are the two poles in every magnet
North and south
like poles ____
repel
opposite poles _____
attract
what does the thumb do in the left-hand rule of an electromagnet
points in the direction of current (negative to positive)
what do the fingers do in the left-hand rule
they curl in the direction of the magnetic field lines
how can you modify the intensity of a magnetic field with an electromagnet
The type of wire and the current intensity
what is the law of conservation of energy
Energy cannot be created nor destroyed; it could only be transformed or transmitted
The total amount of energy within a closed system always remains what
equal
what is the equation for energy efficiency
amount of useful energy/amount of energy consumed x100
acids have a pH of what on the pH scale?
0-6.9
