The observation, identification, description, experimental investigation, and theoretical explanation of phenomena is all part of science. Nothing is immune to the scientific process: from charm quarks that haven't existed naturally since the beginning of time to Pluto, recently demoted from planet to dwarf planet. Questions on knowledge about the material and physical aspects of our world are asked and answered here.
Asked in Science, Chemistry, Periodic Table
What is the fourth element of the periodic table of elements?
What instrument measures mass?
Traditionally a balance was used to measure mass. Objects of known or accepted mass was balanced against another object of unknown mass. When the balance was level the two pans had the same mass. The term balance or scales is still used even though there is no balance used. The scales were the pans that the objects sat on. Now electronic balances are used that gauge the mass of the objects. While you can measure mass with a spring loaded scale, it is less accurate than a balance as it relies on a spring loaded to a specific acceleration of gravity for any given mass. A change in altitude will change the results given on the scale, due to the actual change in gravitational force (it is small at only about 0.031% error for every kilometer increase in altitude)*. A balance would experience no such change as the mass of an unknown quantity is compared to the mass of a known quantity, thus negating any effects of gravity. Another instrument that measures mass is an inertial balance. An inertial balance doesn't require gravity to work, so it can be used in space. It measures the mass of an object by attaching it to a spring and seeing how it affects the spring's period of oscillation. Very tiny masses can be measured directly (using a "massometer"). But we normally use scales, which measure weight, which is directly proportional to mass (a property of matter equal to its resistance to a change in speed or direction of travel). The mass of an object is the same everywhere in the universe. Its weight, however, changes depending upon its location: a bowling ball has greater weight on the surface of the Earth than it does on the Moon. Great confusion arises when people interchange units of weight with units of mass. Scientists, particularly physicists, are very careful about not using the terms interchangeably, but regular folks have no choice for practical applications. For example, when you weigh a regulation ten-pin bowling ball, the scale will tell you it "weighs" between 4 and 7 (3.63 to 7.27 actually) kilograms, even though the kilogram is, technically speaking, a unit of mass, not weight. You can also measure the mass of an object using a scale, as long as you factor in the gravitational constant (G). For instance, in an environment with only 1/2 the gravity of That on earth, you would have to double the weight displayed on the scale to determine the actual mass. As an example, 10Kg of lead in a 0.5G environment would only "weigh" 5Kg on a scale...half as much as on earth, even though its mass is unchanged.
Asked in Science, Scientists
What is the scientific attitude and what attitudes and characteristics define a good scientist?
A good scientist should possess the following qualities: 1. A scientist must be curious about the world Example: Galileo Galileo's curiosity about the heavenly bodies made him the first person to use a telescope to study the moon, the sun, the planets and the stars. 2. A scientist is logical and systematic Example: Among the reasons why Gregor Mendel discovered the principles of heredity when others have failed was his logical experimental methods and his careful and accurate record keeping. 3. A scientist is open-minded and free of bias Example: An open-minded person is one who can modify plans or discard hypotheses if necessary. One such person was Johannes Kepler who was hired to develop evidence that planets moved along perfect circles. 4. A scientist is intellectually honest Example: Isaac Newton built his laws of motion on the previous work of Galileo and others. 5. A scientist works hard and is persistent Example: Marie Curie was the first person ever to be awarded the Nobel Prize twice. It was not surprising considering how hard she worked. 6. A scientist does not jump to conclusions Example: John Dalton's atomic theory was backed by experimental evidence. He was not the first to propose that the atom was the smallest particle of matter, but he was the first to use experimental evidence to support his theory. 7. A scientist is a creative and critical thinker Example: Albert Einstein was able to derive his theory of relativity because he went beyond what was given and known at that time. He saw links and connections where others did not. He looked at things from different perspectives. 8. A scientist is rational 9. A scientist is willing to suspend judgment until he is sure of his results 10. A scientist tries new approaches to arrive at solutions In addition: A scientist must have an open mind and be curious. It is fine to have an idea about how or why something is the way it is, but the scientist should then seek to prove or disprove this "hypothesis" and should then be willing to change their ideas depending on the results of their experiments, rather than to continue believing in their original idea even if the evidence of their experiments is sticking up against it. 1.Keen Observer 2.creative 3.patient 4.curious 5.humble 6.intellectually honest 7.objective 8.Aware of the limitations of Science 9.Persevering 10.Open minded
Asked in Science, Earth Sciences
What is the rock cycle song?
SEDIMENTARY rock Has been formed in layers Often found near water sources With fossils from decayers Then there's IGNEOUS rock Here since Earth was born Molten Lava, cooled and hardened That's how it is formed These two types of rocks Can also be transformed With pressure, heat and chemicals METAMORPHIC they'll become (sung to the tune of row row row your boat) (=**=) (<cat lol)
Asked in Science, Chemistry, Acids and Bases
What are some examples of chemical and physical changes?
Physical Changes Change of state (such as from solid to liquid or from gas to liquid) Specific examples of state change include water freezing, alcohol evaporating and dry ice (solid carbon dioxide) subliming Absorption of water into a towel Crumpling a piece of paper Pulling copper into a thin wire - a change of shape, but not a change of composition Cutting a material such as wood Tearing a piece of tin foil Breaking glass Deflating a basketball Mixing different solids (such as solid sulfur and iron filings) Inflating a volleyball Cloud forming in the sky Chemical changes Burning a log of wood Mixing an acid with a base, producing water and a salt. Photosynthesis - a process in which carbon dioxide and water are changed into sugars by plants. Cracking heavy hydrocarbons to create lighter hydrocarbons (part of the process of refining oil). Cooking examples: popcorn, cake, pancakes, and eggs Oxidation examples: rust or tarnishing Combustion Mixing chemicals Rotting of fruit Cooking rice Explosion of fireworks Tarnishing silver Lighting a match Chewing/digesting food Rusting nail Burning gas in a stove Oxidizing food for energy Roasting a marshmallow Adding food coloring to icing Frying an egg Burning a magnesium strip The following can indicate that a chemical change took place, although this evidence is not conclusive: Change of color (for example, silver to reddish-brown when iron rusts) Change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat Change of form (for example, burning paper) Light, heat, or sound is given off Formation of gases, often appearing as bubbles Formation of precipitate (insoluble particles) The decomposition of organic matter (for example, rotting food)
Asked in Science, Atomic Mass
What is gold's mass number?
The only stable, and only naturally-occurring isotope of gold has mass number of 197. This is the number of protons and neutrons in each nucleus. Gold's atomic number is 79. This is the number of protons found in each gold atom. This determines its place in the periodic table, and its chemical properties: it is the defining property of gold. A nucleus with a different number of neutrons and the same 79 protons would be a different isotope with a different mass number; a nucleus with a different number of protons would not be gold, but some other element.
Asked in History of Science, Science, Superstitions
What superstitious beliefs have a scientific basis?
Superstitious belief, by definition, have no scientific basis. Science requires that ideas are tested in a way that is repeatable and falsifiable. Falsifiable means that there must be a way that the test shows that a stated belief is not true, while most superstitions rely on metaphysical entities or powers that are so vague they can not be dis-proven. Here are some examples of superstitions, and where they may have come from. Breaking a mirror is seen as seven years of bad luck from a historical root. Back in the medieval times mirrors were very expensive. And if you broke one, it was reguarly someone important, such as the lord of the kingdom of the king or a high-ranking nobleman. And if you broke it, it was common that if they were un-forgiving, they would put you in jail, possibly for seven years. Walking under a ladder is seen as bad luck Typically a ladder means someone at the top of the ladder and that person can easily drop things - onto your head. So it really is a bad idea to walk under one. Never sweep the floor at night or you'll sweep sorrow into your life. You may not be able to see where you're sweeping and fall and get injured. Chase away any owls outside your window; they are a harbinger of death. They may erode your windowsill by pecking on it, and when you lean on it, it may break and you may fall. Never start or buy anything on a Friday. Since Friday is the last business day, you or your order will probably not be active on the weekend. Cut your hair on a full moon and it will grow back faster. Well, if you cut your hair at a barber's shop, and you can see the moon, the barber will probably bee in a hurry to leave and so will give you a shorter haircut. Crickets in your home are good luck (not in my home and definitely not for the nasty crickets!) They tell the temperature. Killing a spider is bad luck. In addition to reducing local disease-carrying insects, spiders provide humans with other medical benefits. Spider venom is used in neurological research and may prevent permanent brain damage in stroke victims. The silk produced by spiders is used in many optical devices including laboratory instruments. Ivy growing on a house protects the inhabitants from witchcraft and evil. Evil may mistake it for poison ivy and stay away. Friday the 13th is unlucky The Templars were all arrested (and most were tortured and executed) one Friday the 13th! Actors believe that using real money as a prop is bad luck. This is probably rooted in the fact that leaving real money on stage or in your costume means that there is a good chance that the prop will disappear before the next performance. Opening an umbrella in the house is bad luck. Like walking under a ladder, this is just a hazard; you could hit someone or break something. Bad luck comes in threes. This is sometimes expressed in notable deaths occurring in threes. In fact, this is a well-known psychological bias known as "confirmation effect"; when two events occur, people naturally anticipate a third (two things don't form a pattern, but three do). When the expectation is satisfied, it "proves" the adage. Of course, if it is not, then the pattern is not recognized.
Asked in Science, Urinary System
What are the tubes called that carry urine away from the kidneys to the urinary bladder?
As I believe has already been stated the Ureters, which are also the source of blockages from kidney stones. Not where they come from that is but where stones large enough usually 5 mm can cause blockages. 2 and 3 even 4 mm stones csn take up to 45 days to pass but usually do. The danger is if stones are present in both Ureters and are causing blockages then the urine can back up and seep into your abdomen and cause infection throughout, this is called sepsis and is life threatening which can kill you in a matter of hours. They usually implant a stint bypassing the Ureter to avoid such an incident, the good news is your body was designed with redundancies. You only need 1/3 of 1 kidney to sustain bodily function.
Asked in Science, Earthquakes, Plate Tectonics
What is the process that powers plate tectonics?
Asked in Science, Cooking Equipment
Why is the pan handle made of plastic?
The first and last answers simply are not correct, nor do they answer your question. The second, middle question is much better, but it does not fully answer your question either. If a metal pan with a plastic handle is put in the oven at, let's say, 350 deg., then the temperature of the entire pan, metal and plastic, will eventually reach 350 deg. It is not true that the plastic won't get hot, actually it should heat up faster than the metal. There are two properties in consideration: heat capacity and thermal conductivity. Metals in general have large heat capacities. One can think about the amount of heat a substance can store per unit mass, called the "Specific Heat," or one can consider the amount of heat a substance can store per unit volume. In the case of a pan and handle, it makes more sense to look at the question in terms of the heat stored per volume. Most people know from everyday experience that metals stay hot longer than non-metals like wood and plastic. That is because metals have a much larger heat capacity per volume than most non-metals; that is they hold more heat. What about thermal conductivity? In this case, we only need to consider the thermal conductivity of air. Heat flows FROM a hotter object TO a cooler object. If a pan w/ plastic handle is put in a 350 deg. oven and allowed to heat up completely, when it is taken out the oven the pan and handle are at 350 deg. We only need to consider the heat transfer from the metal to the air and from the plastic to the air. Since the cooler material is the air, all that matters is the thermal conductivity of the air. You can look up thermal conductivities in a table, but air, and all gasses, have much lower thermal conductivities than almost any solid, and it is certainly lower than the pan and Bakelite® (the pan's handle). Since the handle does not contain as much heat as the pan, it will cool down to a touchable temperature faster. The same applies if the pan is placed on a burner. The handle will take longer to heat up than the metal because 1) the metal is directly over the flame, and 2) the metal has a higher thermal conductivity than the plastic meaning that a lot more of the heat from the burner will be absorbed by the metal. Answer The reason the pan Handle is made of plastic is because Plastic is not a conductor of heat so it won't get hot. If the handle was metal it would get very hot because it is a conductor of heat. Answer Frying pans have plastic handles because plastic is a terrible conductor of heat that is coming from a stove. Therefore the handle is cool even when the metal of the frying pan is hot, when you need to lift it, or perhaps something else. Answer Safety. Plastic will not conduct either heat or electricity, so in order you can safely handle pots and pans, plastic is used for those reasons. Conductivity of air plays practically no role in this. If the pan heats up air in contact, that air is immediately removed by convection and replaced by cool air.
10 examples of physical change and chemical change?
Physical Change: *Milo dissolves into hot milk *A plate is dropped and shatters *Grass in mowed *Metal Knife is sharpened *Breakfast Cereal goes soggy Chemical Change: *Wood burns to form black charcoal * A green tomato ripens and turns red * Fireworks explode to form colourful light and loud sounds * Vegetables scraps in the compost bin decompose to form rich soil * An egg is cooked to become a white and yellow solid
What is an alternative to bicarbonate soda?
Depends on what reciepe you are using and what the purpose is: I often use yeast but in some recipes depending on the fluffiness of the cake I will sometimes use baking soda. A friend of mine uses "fizzy water" (carbonated water) as an alternative. Yeast is only used in bread related recipes, whereas bicarb can be used n cakes ~ Baking Soda in a recipe is to help with 'spreadability of the cookie or cake. You don't use it in pancakes so you want the batter to 'stay put'. In a cookie, you want it to spread out a bit, in the cake, you want it to fill in the space of the pan. Baking Soda and Baking Powder CAN be used for each other in a subbing situation. They are both considered leavening agents. In choosing to substitute one for the other you have to know the ratio AND the fact the flavor WILL be DIFFERENT. 1 TSP of Baking Soda needs 3 TSP of Baking Powder. OMIT all SALT. Reverse it to use soda instead of baking powder. You can also use 2 tsp soda and 1 tsp cream of tarter to create BAKING POWDER. Again, omit the salt from the recipe. AGAIN, any substitutions of ingredients, expect flavor change to happen.
Asked in Science, Physics, Chemistry, Chemical Bonding
Why does water have a high and specific heat capacity?
First, we need to know a little bit about water. Water is a polar molecule because oxygen bears partial negative charge and hydrogen bears partial positive charge. This results in extensive hydrogen bonding in water molecules between slightly negative oxygens and slightly positive hydrogens. Second, we need to remember that temperature is another way of saying the average kinetic energy of particles - the higher the temperature, the faster they move, in the case of gases and liquids, or vibrate, in the case of solids. Third, heat capacity is the ability of matter to absorb thermal energy. One calorie is defined as the amount required to heat a gram of water one degree Centigrade. That same calorie will heat a gram of gold 33 degrees. Water's specific heat is defined as 1. The specific heat of gold is therefore .03. Water has a high specific heat because there are quite a few ways water can store heat. 1. Moving along three axes 2. Rotating the "V" shaped molecule in three different directions 3. Hydrogen atoms vibrating back and forth like a tuning fork 4. Hydrogen atoms vibrating up and down along their H-O axis. Finally, the heat of fusion of water is 80 calories per gram, and the heat of vaporization for water is 540 calories. So ice can absorb 80 times as much heat while melting as the same mass of water. Water absorbs 540 times as much heat while turning into water vapor as the same mass of water absorbs. Both phase changes occur at constant temperature, 0 Centigrade and 100 Centigrade respectively. Look up phase change graph for water to see the interesting line.
Asked in Science, Biochemistry, Reference Books
Could somebody suggest some good books on biochemistry to read to put on personal statement?
Asked in Chemistry, Science, Sports
Why is science defined as a product and a process?
This is because science is not just the information presented (the product), but also the way in which that information has been collected (the process). While scientific knowledge should be testable and falsifiable (according to Karl Popper), the way in which such information has been gathered is also important. Science should be unbiased and experiments should be repeatable by different individuals. There are different philosophers who argue on the way science proceeds. (see Popper, Kuhn, Lakatos and Feyerabend)