Hughes' Final
ZnS+O2➡ZnO
not balanced
what type of bonding might you expect between two potassium atomic number 19
not ionic or nonpolar or polar covalent
why do nonpolar substances tend to boil at relatively low temperatures
not much heat is required to separate nonpolar molecules from each other
when two different elements combine to form a compound the resulting properties of a compound are
not necessarily anything like those of the two elements
can be made into thin sheets
physical
consider a ring with a gap in it when the ring is heated the Gap becomes
wider
compared to the mass of a hydrogen atom the mass of an oxygen atom is
16 times greater
what is the total number of protons and neutrons in a water molecule
18
the atomic size of an iron atom which has 26 protons and 27 neutrons in its nucleus is
26
which of these locations experiences the least change in
Hawaii
if two protons and two neutrons were added to oxygen the element resulting would be
Neon
which have been around longer the atoms in a newborn baby or those in the older person
about the same older than the solar system
most chemists focus on
applied research to provide us with new technology
explain why putting a dented ping pong ball in a pot of boiling water will help remove the dent
as air inside the ball is heated it expands and pushes outward on the dentist Boston a dented ping pong ball can be put back in a rounded shaped this way
pour a liter of water of 40 degrees C into a liter of water at 20 degrees C and the final temperature of the two becomes
at or about 30 degrees Celsius
during a chemical change
atoms change Partners to form a new material
3Fe2O3+C➡2Fe3O4+CO
balanced
CH4+2O2➡CO2+2H2O
balanced
if a pair of helium nuclei are fused together the result is
beryllium
if two protons and two neutrons were removed from oxygen the element remaining would be
carbon
turns into a white powder when heated in the presence of oxygen
chemical
if an element of atomic number 118 is ever synthesized it would be
chemically inert, a gas at room temperature and Radioactive
to slightly increase the volume of some 4 degrees Celsius water you should
cool or heat it
aluminum has a specific heat capacity more than twice that of copper Place equal masses of aluminum and copper wire in a flame and the one to undergo the fastest increase in temperature will be
copper
if you pour some 30 degree Celsius water into some 20 degrees Celsius water the final temperature
depend on the relative amounts of water
an infant gains 10lb why would you consider this to be an example of a chemical reaction
during a chemical change new materials are being formed which is certainly the case with a growing human being new hair new fingernails new skin new cells everywhere
atoms of a covalent bond are held together by the
electrical attraction two nuclei have for shared electrons
what elements tend to form ionic compounds
elements found on opposite sides of the periodic table
elements in what portion of the periodic table tend to form covalent bonds
elements in the upper right hand side
if room temperature water is put in a vacuum it rapidly boils. Then the boiling water turns into ice what is your explanation
evaporation has to do nothing with he input but I mastered pressure by decreasing atmospheric pressure evaporation increases because with less obstruction to the change in Phase more molecules are able to leave the water since evaporation and therefore boiling is a cooling process the more energetic one goes from water to vapor water temperature drops when the temperature drops to 0 degrees Celsius freezing that's why in a vacuum water will boil to form ice
true or false a sodium chloride is toxic because of the sodium metals that it contains
false
true or false chemical equations are balanced by modifying the subscripts of chemical formula data
false
true or false molecules are of the microscopic Realm
false
true or false protons and neutrons have the same magnitude of electric charge
false
true or false the freezing of water is an example of a chemical change
false
true or false total amount of all energies in a substance is its temperature
false
true or false water expands when heated from 0 degrees Celsius to 4 degrees Celsius
false
true or false when an atom loses an electron it becomes larger in size
false
which of these laws of thermodynamics has no exception
first law which is basically the law of conservation
the elements copper silver and gold are in the same
group
consider molecules of hydrogen gas and molecules of heavier oxygen gas that have the same kinetic energy the molecules with more speed are
hydrogen
from top to bottom in any given group atomic size
increases
for most all items compared with the atomic number the atomic mass is
larger
in the periodic table elements that are relatively larger in size appear in the
left part of the table
place a 1 kilogram block of aluminum at 30 degrees C into a liter of water at 20 degrees Celsius and the final temperature of the two becomes
less than 30 degrees C
are atoms made of molecules or are molecules made of atoms
molecules are made of atoms
why do we say electrons most affect an atom size of protons and neutrons most affect an atom's mass
most of the mass of an atom is in its nucleus each proton and neutron has amassed nearly that of an electron electrons around the nucleus determined in the items diameter electrons affect an atom size and nucleons its mass
classify flouroacetylene as a polar or non-polar compound
nonpolar
2NaHCO3➡Na2CO3+H2O+2CO2
not balanced
most of the mass of an atom is in its
nucleus
most of the size of an atom the space it occupies is in its
nucleus
to say a chemical equation is balanced means the
number of times each element appears as a reactant equals the number of times it appears as a product
explain what is meant by saying it's mometer measures its own temperature
objects in the same kalidy will ultimately come to the same temperature when hot things cool and cool things warm this is what if the monitor does thermometers come to thermal equilibrium with their surroundings and show this on their scale
a solid is not considered fluid because
of the fixed arrangement of its atoms or molecules
which is the most polar bond in the chemical structure shown below with 7 hydrogen 2 carbon 1 nitrogen and one oxygen
oxygen to hydrogen
conducts electricity
physical
turns into a silvery liquid when heated in the absence of oxygen
physical
a material made of which molecule should have the higher boiling point
picture with two chlorines two carbons and 2 hydrogens
keep heating a gas and you'll have a
plasma
the boiling temperature of water H2O is much higher than that of methane CH4 because water molecules are
polar
which would produce a more highly valued element adding or removing a proton from the element gold
removing a proton gold then turns into more valued Platinum adding a proton Turns Gold into Mercury which is this valuable
in the periodic table of the elements periods normally appear in
rows and groups in columns
the difference between a cup of hot chocolate and a cup of cold chocolate has to do with the differences in molecular
speeds
which will warm up faster on a sunny day the water in a puddle or the sand that surrounds the puddle
the sand
an individual carbon oxygen bond is polar yet carbon dioxide CO2 has two carbon oxygen Bonds is nonpolar because
the two carbon oxygen Bonds in CO2 are oriented 180 degrees from each other
distinguish between the concepts of heat temperature and thermal energy
thermal heat measured in calories are joules is the energy something has by virtue of the molecular motion of its molecules the more molecular kinetic energy the more thermal energy temperature is that kinetic energy per molecule in a substance measured in degrees or kelvin is a thermal energy that transfers from one place to another by virtue of the temperature difference heat like thermal energy is measured in calories to joules
a popular use of a bimetallic strip is in
thermostat
radon atomic number 16 is a radioactive noble gas helium is there a non radioactive noble gases are continually emitted from the surface of the Earth which has a greater tendency to settle into the basement of homes and why
they don't know have a greater tendency to set on the basements of homes because it is heavier basements therefore should be well ventilated helium is much lighter and tends to rise
the lanthanides and actinides are periods of elements that are difficult to purify
true
the noble gases are the least able to combine with other atoms
true
true or false a compound is made of atoms from different elements
true
true or false atoms may be held together by an exchange of electrons
true
true or false most of the atoms in the periodic table are metals
true
true or false polar molecules tend to be attracted to one another
true
true or false positive ions result from the loss of electrons
true
true or false solid matter is mostly empty space because the atoms that comprise that are themselves mostly empty space
true
true or false the energy that transfers from one object to another because of a temperature difference
true
true or false the first law of thermodynamics is simply the conservation of energy applied to Thermal systems
true
true or false there are two electrons for every covalent bond
true
true or false there is a lower limit to how cold something can be
true
the physical properties of a compound are
uniquely different from the physical properties of the elements from which it is made
when ice floats in water a small portion extends above the surface interestingly enough the volume of the ice extending above the surface is equal to the volume of the
vast number of open spaces in the hexagonal ice crystals