Science Tips
Read these 64 Science Tips tips to make your life smarter, better, faster and wiser. Each tip is approved by our Editors and created by expert writers so great we call them Gurus. LifeTips is the place to go when you need to know about Academic tips and hundreds of other topics.
Chemistry - Molarity
M: Molarity is defined as the number of moles of solute per liter of solution.
Chemistry - Beta Particles
BETA particles are the same as electrons, but originate from within the nucleus and have the nuclear symbol:
0
e
-1
Chemistry - Exothermic Change
EXOTHERMIC change is one in which thermal energy is given off. The
temperature of the system goes up.
Chemistry - Chemical Thermodynamics
CHEMICAL THERMODYNAMICS (thermo = heat, dynamics = movement, so, heat
movement) is the study of energy and its interconversions.
Chemistry - Mass Number
The MASS NUMBER, A, equals the sum of the number of protons and neutrons present in the nucleus.
Chemistry - Electrons
ELECTRONS are extremely small particles (much smaller than an atom) with a unit negative charge.
Chemistry - Mass%
MASS % is the ratio of the mass of a component to the total mass of a sample times 100.
Mass % = (# g solute / # g solution) x 100.
Chemistry - 2nd Law of Thermodynamics
SECOND LAW OF THERMODYNAMICS: In any spontaneous process there is always an increase in the entropy of the universe
Chemistry - Homogeneous Mixtures
HOMOGENEOUS MIXTURES have only one phase. They have the same properties throughout a sample, although the properties of different samples may be
different.
Chemistry - Concentrated solutions
CONCENTRATED solutions have a relatively large amount of solute.
Chemistry - Strong Bases
The hydroxides of all IA metals and of Ca, Sr, Ba, (and Ra) in Group IIA are strong electrolytes.
Chemistry - Unsaturated Solutions
UNSATURATED solutions contain a lower concentration of solute than a saturated solution.
Chemistry - Strong electrolytes
Completely ionized in solution - in the conductivity apparatus, the light is bright.
Chemistry - Nonspontaneous Change
NONSPONTANEOUS change can be made to take place by supplying energy.
Chemistry - <=> symbol
<=>: This symbol is used for the double arrow of an equilibrium reaction.
Flora and Fauna
Keeping wildlife or growing green things are a wonderful addition to a unit study. There's nothing like actually seeing the topic of your study up close. We have hatched butterflies and sea monkeys, grown corn and other plants and will be hatching tadpoles this spring.
How to solve tough science problems?
Tough science problems are less intimidating once you
analyze them - once you figure out what kind of problem it is and what kind of principles and procedures are relevant to solving it. To be an expert problem solver, look for essentials. Get in the habit of asking:
* What is the problem about? What are you being asked to find?
* What information is relevant? What principles are
relevant?
* What do you know about similar problems? How did you solve those? What's different here?
* What methods should you follow to use the information you have to solve the problem?
* Does your solution makes sense?
The amateur problem solver starts plugging numbers into equations right away. He tries to solve the problem by brute force. Expert problem solvers get the lay of the land first. To be an expert, know what you're doing - and why.
Newspaper Activities
Have students look up the high and low temperatures for your community. Compare the temperature where you live with other parts of the country. Have them find the highest and lowest temperature.
Extend this activity by having students write about the climate in either the city with the highest temp or the lowest temp.
Chemistry - Solute
A SOLUTE is the solution component present in a smaller amount than the solvent.
Chemistry - Nuclear Equations
NUCLEAR EQUATIONS show the changes that take place in the nuclei. They are similar to chemical equations in that reactants are shown to the left of the arrow and products are shown to the right of the arrow.
Chemistry - Atomic Number
The ATOMIC NUMBER, Z, is the number of protons present in the nucleus of an atom. In a neutral species, it is equal to the number of electrons present in the atom.
Chemistry - Acid
A substance that increases the concentration hydrogen ions when dissolved in water.
Chemistry - Gamma Rays
GAMMA rays are high energy (higher energy and shorter wavelength than x-rays) electromagnetic radiation which are usually given off when a nuclide decays. Gamma rays are usually not shown in nuclear equations since they have no mass or charge.
Chemistry - Equilibrium
EQUILIBRIUM occurs when the forward rate of change equals the reverse
rate of change.
Chemistry - Acid Dissociation Constant or Acid Ionization Constant
It has the symbol Ka and is the equilibrium constant expression for the ionization of a weak acid.
For any weak acid, HA, Ka = [H^+][A^-] / [HA].
Chemistry - Nucleus
The NUCLEUS is at the center of the atom and is small, dense and positively charged.
Chemistry - Strong Acids
HCl, HBr, HI, HClO4, HNO3, and H2SO4 are all strong electrolytes. All other common acids are weak electrolytes.
Chemistry - Nonelectrolytes
No ions present in solution - in the conductivity apparatus, the light is out.
Chemistry - Isotopes
ISOTOPES are elements with the same number of protons, but different numbers of neutrons, that is the atomic number is the same, but the mass numbers are different.
How to teach the impact of the shape of earth on weather?
Younger students may have a problem to understand the impact of the shape of Earth. One of the ways to teach them, is through a "pick" to a "sister-class" in the Southern Cone (or the Northren, if you're in the Southern). They will see and learn that while we have winter, they have summer (make them write an essay about the different impacts, for example, Chritmas in the summer).
Chemistry - Le Chatelier's Principle
LE CHATELIER'S PRINCIPLE: If an equilibrium is *disturbed*, - changed in some way - processes occur that tend to partially counteract the *disturbance*,
and thus bring the system to a new position of equilibrium. The system *shifts* so as to reduce the effect of the change.
Chemistry - Nuclear Symbol
A NUCLEAR SYMBOL is a symbol for an individual nuclide. It has the form:
mass number - A
chemical symbol - X
atomic number - Z
Chemistry - Isotopes
ISOTOPES are elements with the same number of protons, but different numbers of neutrons, that is the atomic number is the same, but the mass numbers are different.
Chemistry - Percent Dissociation or Percent Ionization
Percent dissociation or Percent ionization: Percent is equal to the part divided by the whole times 100: So, percent ionization is equal to the fraction of the solute that is ionized times 100. For a weak acid,
this gives: [A^-]eq
% ionization (HA) = -------- x 100
[HA]init
Where [A^-]eq is the concentration of the anion at equilibrium, and [HA]init is the initial concentration of the weak acid.
Chemistry - Radioactive Decay
RADIOACTIVE DECAY are nuclear reactions that involve the protons and neutrons that make up the nucleus.
Chemistry - Vapor Pressure
EQUILIBRIUM VAPOR PRESSURE or VAPOR PRESSURE: The pressure of the vapor in equilibrium with a liquid - depends on the strength of the
intermolecular forces of the liquid and on the temperature.
Chemistry - Nucleons
NUCLEONS is a term used to refer to both protons and neutrons in the nucleus.
Chemistry - Alpha Particles
ALPHA particles are helium nuclei and have the nuclear symbol:
4
He
2
Chemistry - Dynamic Equilibrium
DYNAMIC EQUILIBRIUM: the rates of change in the forward and reverse directions are equal.
How To Use The Scientific Method
The Scientific Method is a systematic way to find answers to questions that interest you. The following five steps will make the documentation of your science experiments easier.
1. Question: Make observations and develop your question. The question should be about what you are interested in learning or what you want to know.
2. Hypothesis: State your hypothesis. Your hypothesis is your educated guess about what you think will happen.
3. Method: The method is the process or steps of your experiment. This should be very detailed and include materials needed.
4. Results: The results are the facts or data that you collect from your experiment.
5. Conclusion: In the conclusion, you explain why you think the experiment happened the way it did. Include whether the results supported your hypothesis or not.
Chemistry - Supersaturated Solutions
SUPERSATURATED solutions contain more than the equilibrium concentration of solute that is present in a saturated solution.
Chemistry - Endothermic Change
ENDOTHERMIC change is one which thermal energy is absorbed. The temperature of the system goes down.
Chemistry - Saturated Solutions
SATURATED solutions contain as much solute that will dissolve at a given temperature in the presence of excess solute
Homeschooling - Dissection
Try dissecting a freshly caught trout for a unit on Fish. I had a friend who brought home a dead rabbit discovered on a morning walk for her children to dissect during the day's homeschool session. Always wear gloves and take safety precautions when dissecting wild specimens. See my link for virtual frog dissections to get some practice.
Chemistry - Solvent
A SOLVENT is the substance (usually a liquid) which is the major component of a solution.
Chemistry - 3rd Law of Thermodynamics
THIRD LAW OF THERMODYNAMICS: the entropy of a perfect crystal at 0 Kelvin in zero.
Chemistry - Valence Electrons
VALENCE electrons are the electrons in the outer shell that are involved in chemical reactions.
Chemistry - Weak Electrolytes
Partially ionized in solution - in the conductivity apparatus, the light is dim.
Chemistry - Protons
PROTONS are small particles with a unit positive charge present in the
nucleus.
Preventing Science Slips
1. Plan carefully. Write out even the minutest detail ahead of time.
2. Allow time for last minute difficulties. Hardly anything ever works exactly right the first time. Make sure that you don't try to cram a 25 minute experiment into 15 minutes!
3. Trust your instincts. If the experiment seems like it might be dangerous or faulty, check with an expert before proceeding.
4. Follow instructions exactly. Now is not the time to cut corners and it could even be dangerous.
5. Don't be afraid to elaborate.While this may seem contradictory to the preceding tip, feel free to expand the experiment where safety is not a concern. Part of the discovery process is asking "What would happen if we did this?".
6. Turn failure into learning oppotunities. If the experiment fails, instead of chucking it, go back and search for reasons why it failed.
Chemistry - pH
pH is defined as the negative of the base ten logarithm of the molar concentration of hydrogen ion. pH = -log[H^+]. Remember, the first # in a pH value is just telling the power of 10 or the # of decimal places. So, use the # of digits after the decimal point to determine the # of significant figures for [H^+].
Chemistry - 1st Law of Thermodynamics
FIRST LAW OF THERMODYNAMICS: the energy of the universe is constant - energy cannot be created or destroyed.
Chemistry - Base
A substance that increases the concentration of hydroxide ions when dissolved in water.
Chemistry - Electrolytes
Compounds that conduct elecricity when dissolved or melted. Three types of compounds are electrolytes: acids, bases and salts. Substances maybe classified as Strong Electrolytes, Weak Electrolytes, or Nonelectrolytes.
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