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Science Experiments
Experiments often conducted by students to test different scientific theories and hypotheses
11,111 Questions
How different types of light affect plant growth?
The photosynthetic pigments of plants are more productive with certain colours of light. Green plants appear green as they have no need for green light; use only violet, orange, and red. Red Algae has no need for red light and only uses the higher frequencies.
How do you determine when a loop is cool?
Touch it to the sterile agar in a plate. If it melts the agar, it is still hot. If it doesn't melt the agar, then it is cool enough.
Why is the fulcrum in a lever important?
A fulcrum in a lever is very important because without a fulcrum a lever isn't a lever , and the fulcrum is the main part of a lever.
Wind exists because of two main forces: The rotation of the earth, and the heat and light from the sun.
The rotation of the earth causes wind because the natural tendency of air molecules is to stay still. The earth essentially is moving, and the air is essentially staying where it is, creating the illusion that the air is moving. This is called "the Coriolis Effect". The Coriolis effect is what causes the constant unchanging winds used by sailing ships.
The heat from the sun is responsible for almost all of earth's weather, except for those mentioned above. The sun's heat causes the air molecules to become excited, and lack of heat makes the molecules stand still. Excited molecules expand, and create High Pressure. Still molecules contract and create low pressure. When high pressure air moves in to fill in the slight vacuum created by low pressure air, it creates wind.
In short
HOT AIR = HIGH PRESSURE
COLD AIR = LOW PRESSURE
HIGH PRESSURE TRIES TO GET TO WHERE THERE IS LESS PRESSURE.
A) Is the sample a carbonate? NO
B) What are the two compounds that might be the unknown? KHCo3 & NaHCo3
C)Write the chemical equation for the overall reaction that would occur when the original compound was converted to a chloride. If the compound is a hydrogen carbonate, use the sum of Equations 1 and 2. If the sample is a carbonate, use Equation 2. Write the equation for a sodium salt and then for a potassium salt?
2NaHCO3-->Na2Co3 + Co2 + H2o
2KHCo3-->K2Co3 + Co2 +H2o
Na2Co3(s) + 2H(aq) + 2Cl(aq)-->2NaCl(s) + H2o(g) +Co2(g)
K2Co3(s) + 2H(aq) + 2Cl(aq)-->2KCl(s) + H2o(g) +Co2(g)
D) How many moles of the chloride salt would be produced from one mole of original compound? 1 MOLE
E) How many grams of the chloride salt would be produced from one molar mass of original compound?
Molar masses: NaHCO3=84.007g Na2CO3=106g NaCl=58.44 g
KHCO3=100.16g K2CO3=138.21g KCl=74.55 g
If a sodium salt,=84.007g original compound : =54.44g chloride
If a potassium salt,=100.16g original compound : =74.55g chloride
F) What is the theoretical mass ratio, mass chloride/mass original compound?
If she has an Na salt? =0.30 If she has a K salt? =0.26
G) What was the Value of Q? =0.2570
H) Which compound did she have as an unknown? KHCo3
Difference bw ostia and osculum?
ostia is the inlet into the sponge and osculum is the outlet through which the entered water etc. moves out
In an experiment what is the manipulated variable?
A manipulated variable is the thing that can be changed in an experiment.
example; your trying to see what paper towel would be more absorbant, your manipulated viariable would be either the type of paper towel you use or the liquid you use to test the absorbancy.
How do the consumers obtain these nutrients?
Consumers obtain nutrients by consuming a balanced diet composed of a variety of foods including fruits, vegetables, whole grains, lean proteins, and healthy fats. These foods provide essential vitamins, minerals, and other nutrients that the body needs to function properly. It's important to eat a diverse range of nutrient-dense foods to ensure you are getting all the necessary nutrients.
Does sugar dissolve faster than salt when all other variables are the same?
Sugar dissolves in a liquid faster than salt does.
The reason is that sugar is less dense as a solute than salt is, leading to it dissolving in the solvent faster as it would fit into the 'empty gaps' that the solvent has at a much faster rate, which is how substances dissolve.
In energy transformations when a roller coaster is at the top of the hill the kinetic energy is?
Kinetic energy comes from movement. If the roller coaster is moving at the top of the hill, it has kinetic energy. if the rollercoaster isn't moving then it has potential energy.
Why are controls important when testing a hypothesis?
By having a control (which is subjected to the same conditions as the test subject[s] except for the condition or substance you are testing) you can eliminate other influences, by comparing the control to your test. In testing medication, for example, this is VERY important - if only to account for the PLACEBO EFFECT that occurs.
By having a variable, you can compare the results of a series of applications of the specific condition or substance you are testing, which should show at what level(s) the experiment works and possibly what side effects occur.
More Information:
The variable provides the data that are to be interpreted and compared.
The control provides a reference, or standard, for comparison. Without this reference, no valid comparison is possible so, the data is moot, and the hypothesis can't be tested.
A pure substance is matter that has a fixed what?
A pure substance is a substance that cannot be separated by means of physical separation but only by chemical. It is a change in time.
What has a higher specific heat than water?
The specific heat of liquid water is 4.183 J / g K. Lithium liquid has a higher specific heat at 4.379, as does Hydrogen gas at 14.30. Helium gas also does at 5.1932 Finally, liquid Ammonia has a higher specific heat at 4.700.
What is a good title for a science fair project dealing with rubber band elasticity and temperature?
or RUBBER BAND ELASTICITY AND TEMPERATURE
What safety rules should be followed in a science laboratory?
Safety Rules and Procedures
- Know what WHMIS is, and what the Safety Sheets are to look at the different chemicals that are used within the lab environment.
- Know how to use the fire extinguishers, and when it is appropriate to use them.
- Report all injuries and illnesses to lab staff immediately, DO NOT wait!
- If you notice a gas leak, or other sort of leak, make sure that you mention to the lab staff.
- Clean up spills and broken glass and other equipment using the prescribed outlines that are provided by your lab. Some like mercury requires special precautions
- If you hear the fire alarm, close all doors to the lab, and make sure that you quickly turn off everything such as gas, and other components that you may be using. Then evacuate.
- Have regular safety meetings with the lab staff to go through policies and procedures that are needed while in the lab!
- Long hair tied back If you're wearing a tie tuck it inside your blouse/shirt or remove it to avoid accidents.
- If possible, stand up and put stools elsewhere so that if something spills then you can move back faster
- Keep your desk (work area) clean
- Always wear either long sleeves or a lab coat due to splashing of chemicals. In addition, closed toe shoes are a must. So no sandals or flip flops! Be sure to roll up your sleeves or wear a short-sleeved shirt if you're working with heat or open flame.
- No food or drink in the lab - mistakes and contamination can be deadly
- No horseplay or practical jokes (focus on your work)
- Use of potentially dangerous chemicals limited to knowledgeable staff
- No chipped or cracked glassware
- Learn the proper insertion of rubber stoppers into glass tubes
- All cuts burns etc. reported and treated, no exceptions
- All gas cylinders chained to the wall
- No experiment left alone
- No "Wonder what happens if I do this" experiments
- Do not pick up or move flasks or other containers holding chemicals unless absolutely necessary. Fewer mistakes means fewer accidents. When you must move a container, use BOTH HANDS to make sure you have a firm grip, and always make sure your travel path is clear.
- Read all labels thoroughly. Make sure you know what you're using and its proper use!
- Do not rush through instructions - pay close attention to all details, especially any precautions
- always watch out for spills and slippery liquids.
The only safety rules for ANY laboratory that you are thinking about working in are the ones that the laboratory requires and should be clearly explained to you before you even enter it. The rest is opinion.
What is the opposite of thermal energy?
There is no opposite of thermal energy.
Thermal energy is energy that comes from heat, and therefore comparable to temperature. There is no "opposite of temperature," and there is no "opposite of thermal energy."
If an object has high thermal energy, it is hot. The opposite of that would be having low thermal energy, or being cold.
Which of the following is NOT a control for the experiment described in the question below?
Which of the following is not true about controls in an experiment
The freezing point of a substance is always lower than its?
I suspect the intended answer is "boiling point", though strictly speaking that's not true: a material may not haveone or the other of these things at a particular pressure, which makes it problematic to talk about whether or not the one that doesn't exist is "lower" or "higher" than the one that does.
I am pretty sure that the answer "triple point temperature" is strictly true. However, unless you're in a physical chemistry class, your teacher probably doesn't expect you to know what a triple point temperature is, and may not know themselves.
independent variables
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