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Scientific Method
The scientific method is the basis of scientific investigation. A scientist will pose a question and formulate a hypothesis as a potential explanation or answer to the question. The hypothesis will be tested through a series of experiments. The results of the experiments will either prove or disprove the hypothesis. This category should contain questions and answers regarding the scientific method.
4,392 Questions
Who plays Stephanie from the next step?
Shelby Bain plays Stephanie on The Next Step. She is a Canadian actress known for her role on the popular dance-themed television series.
What products can be made using the melting method?
Products that can be made using the melting method include candles, soaps, chocolates, and certain types of cosmetics like lip balms and lotions. This method involves melting ingredients together, which are then poured into molds to solidify into the desired shape.
Why is the burning of wax an irreversible reaction?
When the candle is burned, chemical reactions take place between the wax and oxygen. These chemical reactions release energy in the form of heat and light. These reactions are not going to easily be run backwards. If they did, we might have candles popping up all over the place....
On the other hand, melting the wax is just a phase change. The physical properties change, but the chemical properties do not. Since the wax melts because the temperature of the wax is raised, once the heat source is removed, the wax will begin to lose heat, assuming that ambient temperature is low enough. Eventually, the wax will go through another phase change and become solid.
So, the short answer is: burning is irreversible because it involves a chemical reaction, while melting is reversible because it's just a phase change. The caveat is: the chemical reaction is reversible too. Ever wonder where your ear wax comes from? Candles and crayons aren't a part of a normal diet....
A physical change is when the same compound/chemical just changes form, for example, water experiences physical changes when it goes from ice to liquid to steam. The identity of the compound is completely unchanged however.
A chemical change is one where bonds have changed, therefore the molecule that existed the change is now a completely different molecule. For example, burning glucose in oxygen gives you carbon dioxide and water. Notice the glucose has combined with the oxygen to form completely new chemicals, i.e. CO2 and H2O. (It is worth remembering that burning is a chemical reaction with oxygen).
So in your example, the flame melts the wax and there is a physical change occurring. The wax goes from solid to liquid, but it is always wax, just in different forms If the melted was cools again, it will go back to being the same solid wax as before. When the wax burns, and the wax combines with the oxygen to form CO2, carbon monoxide, carbon particles (incomplete burning/oxidation) and water. After it burns, you can't get the wax back! The burning has broken the bonds in the wax and made new compounds.
Note that when a candle burns, the wax does two things. First it melts, and then it burns. What burns is actually melted wax! The heat of the candle melts the nearby wax, and that melted wax is absorbed by the candle's wick. The melted wax burns on the wick -- the wick itself isn't burning, just the wax on it. However, as the candle burns down, what happens is there isn't enough wax nearby to melt, and so the end of the wick does burn a little, which is why it slowly gets shorter (at the same speed as the candle gets shorter).
It is a chemical change because there is new matter created but flammability is more of a property than a chemical change. A physical change is still the same matter but is in a different form like cutting paper. Its still paper. But if you burn paper, that's a chemical change because its new matter now and its really hard to change back
Yes, it is acetic acid and on heating with soda-lime (CaO+NaOH) produces Methane the ist member of alkanes.
Dose hot boil faster than cold water?
Yes, hot water boils faster than cold water because the molecules in hot water have more energy and are already closer to the boiling point. This means it takes less time and energy to raise the temperature of hot water to the boiling point compared to cold water.
Why is a scientific law called a law?
A scientific law is called a law because it is a statement based on repeated experimental observations that describe a natural phenomenon. It is a fundamental principle that has been universally accepted as true within a specific field of study. Laws help to predict and understand the behavior of the natural world.
Galileo's methodology, which involved observation, experimentation, and mathematical analysis, helped shift the focus of science from relying solely on philosophical arguments to empirical evidence. He emphasized the importance of testing hypotheses through reproducible experiments, which is a fundamental aspect of the scientific method. Galileo's work laid the foundation for modern physics by promoting a methodological approach based on observation and experimentation.
What observation of softdrinks before agitation?
Before agitation, soft drinks typically appear still with the ingredients relatively settled at the bottom of the container. The liquid is typically clear and homogeneous in appearance.
How did Alexander Fleming use the scientific method?
Alexander Fleming used the scientific method by making observations of mold killing bacteria in a petri dish, forming a hypothesis that the mold could have antibacterial properties, testing this hypothesis through experiments, and analyzing the results to draw conclusions. His systematic approach led to the discovery of penicillin, the first antibiotic.
Which step in the scientific method directly follows making a hypothesis?
After making a hypothesis, the next step in the scientific method is to conduct an experiment to test the hypothesis. This involves collecting data and analyzing results to determine if the hypothesis is supported or refuted.
When an experiment shows that one variable makes another variable change the experiment shows?
that there is a relationship between the two variables. This relationship can be used to predict how changes in one variable will affect the other variable.
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Who performs critical evaluation of scientific ideas and methods?
Scientists, researchers, and experts within the specific field of study typically perform critical evaluation of scientific ideas and methods. This involves conducting peer reviews, replicating experiments, and analyzing data to ensure the credibility and validity of the scientific work.
Which part of the scientific method is based a result of an experiment?
The analysis and interpretation of results is the part of the scientific method that is based on the outcome of an experiment. This step involves examining the data collected during the experiment to draw meaningful conclusions and determine if they support or refute the initial hypothesis.
Describe precipitatipn test in serological method?
Serological tests may be performed for diagnostic purposes when an infection is suspected, in rheumatic. These include: ELISA, agglutination, precipitation, complement-fixation, and fluorescent antibodies. Liver function tests: protein tests.
What is the chemical structure of the Naphtha?
Naphtha is a complex mixture of hydrocarbons, typically containing mainly alkanes, cycloalkanes, and aromatic hydrocarbons. Its chemical structure varies depending on the specific composition of the naphtha sample.
What compounds make up bohrium?
Bohrium is a synthetic element that does not occur naturally on Earth. It is a highly radioactive element, with isotopes ranging from bohrium-260 to bohrium-267. Due to its short half-life, bohrium does not form stable compounds and its chemical properties are not well-studied.
How long does a orange to grow mold on it?
It can take anywhere from a few days to a couple of weeks for an orange to start growing mold, depending on how ripe it is, the temperature and humidity of its environment, and whether it has any damage or breaks in the skin.
To be a valid scientific experiment the results must be?
replicable, meaning that they can be reproduced by others following the same procedure. The results should also be objective and unbiased, allowing for accurate interpretation and analysis. Additionally, the experiment should be conducted with proper controls and variables to ensure validity.
Role of spooling in blood DNA isolation?
spooling of the DNA results from the addition of the ethanol which is insoluble in the solution. after we get he DNA in the form of spooling structure the solution is centrifuged. so we get the DNA.
using uv-visible spectrophotometer
concentration vs absorbance is plotted and the maximum absorbance of the drug is lambda max of the drug. then after it will decrease. still if needed clarification, refer beer lambert"s law
What is the name of a magnetized needle that swings freely?
A Compass!
A common science experiment involves rubbing a magnet down a needle (only one way!) and putting it in a "boat" in a bowl of water to demonstrate a simple compass!
The Earth has a core of iron. This makes a magnetic field, with north pointing (almost*) at the north pole, and south at the south pole.
*Magnetic north is not the north pole. Actually, compasses point to a place in northern Canada
What are the similarities between rotation and revolution?
well the difference is rotation is around an axis in the center of a body. revolution is the movement of a body around an axis outside of the body ( earth is the body then the sun is the axis.
