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please help me correct my mistakes if i have any how does an observation abut an object differ frm an inference abut that object? when u observe an object, you do not touch it, all you are doing is studying it. When you interfere with the object you are being physical. 21.how are unicellular and multicellular organisms alike?how are they different? they both have basic unit of life. unicellular organism are like bacterias and such and Multicellular is like us. 24.how can a graph of data be more informative than a table of the same data? With a it is very easy to see the data, and much more organized. 25.what is a cell culture?how can a cell culture be useful to biologists? he process by which either prokaryotic or eukaryotic cells are grown under controlled conditions. It is important to biologist because they can study it and experiment with it.

thanks so much!

So how would i do the 1 with diff base?

Okay, I have a few questions about putting exponents in simplest form .. Example 5^5 x 5^5 = 5^10 just add the exponents 9^5 x 8^5 = 72^10?? I understand how to do it if its the same number but i cant understand if its diff please tell me..

Ive tried my best to answer please, can someone check it? Physical vs. Chemical Properties 1. Red color - Physical property 2. density - physical 3. flammability - physical 4. solubility - Chemical property 5. reacts with acid to from hydrogen - Chemical property 6. supports combustions - Chemical property 7. bitter taste - Phyiscal property 8. melting point - physical 9. reacts with water to form gas - Chemical Property 10. reacts with a base to form water - Chemical Property 11. hardness - Physical property 12. boiling point - physical property 13. can neutralize a base - chemical property Phyiscal vs chemical change 1. Sodium hydroxide dissolves in water - Chemical 2. Hydrochloric acid reacts with sodium hydroxide to produce a salt, water, and heat - Chemical 3. A pellet of sodium is sliced in two - Physical 4. Water is heated and changed to steam - Physical 5. Potassium chlorate decomposes to potassium chloride and oxygen gas - Chemical 6. Iron rusts - Chemical 7. ice melts - physical 8. Acid on limestone produces carbon dioxide gas - chemical 9. milk sours - chemical 10. wood rots - physical Substances vs. Mixture 1. sodium - S 2. water - S 3. Soil - M 4. Coffee - M 5. Oxygen - S 6. Alcohol - M 7. Carbon dioxide - S 8. Cake batter - M 9. Air - M 10. Soup - M 11. Iron - S 12. Salt water - M 13. ice cream - M 14. nitrogen - S 15. eggs - M 16. blood - M 17. table salt - S 18. nail polish - M 19. milk - M 20. Cola - M

there we go, i fixed all i think were wrong.. please check the last 3 sections again for me

so air is a mixture huh? .. i dun see how table salt is a substance.. can you explain? and can you please check the physical and chemical property part

oh dear! i belieave that is M lol thats the only 1 i have wrong?

yeah thanks for helping me still need help with the last 3 sections

this is tricky.. number3

I need someone to check my work and see if it did it right or not. I skip some of them because I do not know them, and I hope you guys can help me. This is my final study guide for my final test in physical science. Please help me out! Calulating Density Density = Mass/Volume 1. What is the density of carbon dioxide gas if 0.196g occupies a volume of 100 mL? ANSWER: 0.00196 g/mL 2. A block of wood 3.0 cm on each side has a mass of 27 g. What is the density of this block ANSWER: 1 g/cm^3 3. An irregularly shaped stone was lowered into a graduated cylinder holding a volume of water equal to 2.0 mL. The height of the water rose 7.0 mL. If the mass of the stone was 25g, what was its density? ANSWER: 5 g/mL^3 4. A 10.0 CM^3 sample of copper has a mass of 89.6 g. What is the density of copper? ANSWER: 8.96 g/cm^3 5. Silver has a density of 10.5g/CM^3 and gold has a density of 19.3 g/CM^3 . Which would have a greater mass, 5cm^3 of silver or 5cm^3 of gold? ANSWER: Gold 6. Five mL of ethanol has a mass of 3.9g, and 5.0 mL of benzene has a mass of 4.4g. Which liquid is denser? ANSWER: Benzene. 7. A sample of iron has the demensions of 2 cm x 3 cm x 2cm. If the mass of this rectangular-shaped object is 94g, what is the density of iron? ANSWER: 7.83 g/cm^3 Acceleration Calculations Acceleration = Final velocity - initial velocity/time Initial Velocity Final Velocity Time Acceleration 1. 0 km/hr 24 km/hr 3s = 8 km/hr/s 2. 0 m/s 35 m/s 5s = 7 m/s/s 3. 20 km/hr 60 km/hr 10s = 4 km/hr/s 4. 50 m/s 150 m/s 5s = 20 m/s/s 5. 25 km/hr 1200 km/hr 2mins = 587.5 km/hr/m 6. A car accelerates from a standstill to 6 km/hr in 10 second. What is its acceleration? ANSWER: 0.6 km/hr/s 7. Acar accelerates from 25 km/hr to 55 km/hr in 30 seconds. What is its acceleration? ANSWER: 1 km/hr/s 8. A train is accelerating at a rate of 2 km/hr/s. If its inital velocity is 20 km/hr, what is its velocity after 30 seconds? ANSWER: 80 km/hr 9. A runner achieves a velocity of 11.1 m/s 9s after he begins. What is his acceleration? What is his distance did he cover? ANSWER: 1.23 m/s/s, distance is 49.95 m Calculating Power Power = Work/time 1. A set of pulleys is used to lift a piano weighing 1000 newtons. The piano lifted 3 meters in 60 seconds. How much power is used? ANSWER: 500W 2. How much power is used if a force of 35 newtons is used to push a box a distance of 10 meters in 5 seconds? ANSWER: 70W 3. What is the power if a kitchen blender if it can perform 3750 joules of work in 15 seconds? ANSWER: 250W 4. How much work is done using a 500W microwave oven for 5 minutes? ANSWER: 2500J 5. How much work is done using a 60W light bulb for 1 hour? ANSWER: 216,000J Determining Speed (Velocity) Speed = Distance/Time Velocity = Distance/time 1. What is the velocity of a car that traveled a total of 75 kilometers north in 1.5 hours? ANSWER: 50 km/hr 2. What is the velocity of a plane that traveled 3000 miles from New York to California in 5 hours? ANSWER: 600 m/hr 3. John took 45 minutes to bicycle to his grandmother's house, a total of four kilometers. What was his velocity in km/hr? ANSWER: 11.25 km/hr 4. It took 3.5 hours for a train to travel the distance between two cities at a velocity of 120 miles/hr. How many miles lie between the two cities? ANSWER: 420 miles 5. How long would it take for a car tp travel a distance of 200 kilometers if it is travelingat a velocity of 55 km/hr? ANSWER: 3.63 hour 6. A car traveling at 100 km/hr. How many hours will it take to cover a distance of 750 km? ANSWER: 7.5 hours 7. A plane traveled for about 2.5 hours at a velocity of 1200 km/hr. What distance did it travel? ANSWER: 300 km 8. A girl is pedaling her bicycle at a velocity of 0.10 km/min. How far will she travel in two hours? ANSWER: .20 km Force and Acceleration Force = Mass x Acceleration 1. With what force will a car hit a tree if the car has a mass of 3000 kg and it is accelerating at a rate of 2 m/s^2 ANSWER: 6000N 2. A 10 kg bowling ball would require what force to accelerate it down an alleyway at a rate of 3 m/s^2 ANSWER: 30N 3. What is the mass of a falling rock if it hits the ground with a force of 147 newtons? ANSWER: Help! 4. What is the acceleration of a softball if it has a mass of 0.50 kg and hits the catcher's glove with a force of 25 newtons? ANSWER: 0.4 m/s 5. What is the mass of a truck if it is accelerating at a rate of 5 m/s^2 and hits a parked car with a froce of 14000 newtons? ANSWER: 2800 kg Heat and Phase Changes For freezing and melting Heat = (mass in grams) x (heat of fusion) For boiling and condensation Heat = (mass in grams) x (heat of vaporization) The heat of fusion of water = 340 j/g The heat of vaporization of water = 2300 j/g 1. How many joules of heat are necessary to melt 500 g of ice at its freezing point? ANSWER: 170,000J 2. How many kilojoules is this? ANSWER: HELP! 3. How much heat is necessary to vaporize 500 g of water at its boiling point? ANSWER: 115,000J 4. If 5,100 joules of heat are given off when a sample of water freezes, what is the mass of the water? ANSWER: 15g 5. If 57,500 joules of heat are given off when a sample of steam condenses, what is the mass of the steam? ANSWER: 25g Calculating Work Work = Force x Distance 1. A book weighing 1 newton is lefted 2 meters. How much work was done? ANSWER: 2J 2. A force of 15 newton is used to push a box along the floor a distance of 3 meters. How much work was done? ANSWER: 45J 3. It took 50 Joules to push a chair 5 meters across the floor. With that force was the chair pushed? ANSWER: 10N 4. A force of 100 newtons was necessaryto lift a rock. A total of 150 joules of work was done. How far was the rock lifted? ANSWER: 1.5 meters 5. It took 500 newtons of force to push a car 4 meters. How much work was done? ANSWER: 2000J 6. A young man exerted a force of 9000 newtons on a stalled car but was unable to move it. How much work was done? ANSWER: No work was done there. Potential and Kinetic Energy Potential energy = weight x height Kinetic Energy = 1/2 mass x velocity^2 1. What is the potential energy of a rock that weighs 100 newtons that is sitting on top of a hill 300 meters high? ANSWER: 30,000J 2. What os the kinetic energy of a bicycle with a mass of 14 kg traveling at a velocity of 3 m/s? ANSWER: 63J 3. A flower pot weighing 3 newtons is sitting on a windowsill 30 mets from the ground. Is the energy of the flower pot potential or kinetic? How much joules is this? ANSWER: Potential, 90J 4. When the flower pot in problem 3 is only 10 meter from the ground, what is the potential energy? ANSWER: 30J 5. How much of the total energy in problem 3 and 4 has been transformed to kinetic energy? ANSWER: HELP! 6. A 1200 kg automobile is traveling at a velocity of 100 m/s. Is its energy potential or kinetic? How much energy does it possess? ANSWER: Kinetic, 6,000,000J Physical vs. Chemical Properties 1. Red color - Physical property 2. density - physical 3. flammability - physical 4. solubility - Chemical property 5. reacts with acid to from hydrogen - Chemical property 6. supports combustions - Chemical property 7. bitter taste - Phyiscal property 8. melting point - physical 9. reacts with water to form gas - Chemical Property 10. reacts with a base to form water - Chemical Property 11. hardness - Physical property 12. boiling point - physical property 13. can neutralize a base - chemical property Phyiscal vs chemical change 1. Sodium hydroxide dissolves in water - Chemical 2. Hydrochloric acid reacts with sodium hydroxide to produce a salt, water, and heat - Chemical 3. A pellet of sodium is sliced in two - Physical 4. Water is heated and changed to steam - Physical 5. Potassium chlorate decomposes to potassium chloride and oxygen gas - Chemical 6. Iron rusts - Chemical 7. ice melts - physical 8. Acid on limestone produces carbon dioxide gas - chemical 9. milk sours - chemical 10. wood rots - physical Substances vs. Mixture 1. sodium - S 2. water - S 3. Soil - M 4. Coffee - M 5. Oxygen - S 6. Alcohol - M 7. Carbon dioxide - S 8. Cake batter - M 9. Air - M 10. Soup - M 11. Iron - S 12. Salt water - M 13. ice cream - M 14. nitrogen - S 15. eggs - M 16. blood - M 17. table salt - S 18. nail polish - M 19. milk - M 20. Cola - M

1. To turn 50g of boiling water to steam requires A. 50 Calories (210 Joules) B. 500 Calories (2100 Joules) C. 540 Calories (2270 Joules) D. None above 2. If you were caught freezing in cold weather with only a candel for heat, you would be warmer in A. an igloo B. a car C. a tent D. a wooden house 3. It is possible to totally convert a given amount of energy into mechanical energy. A. True B. False 4. When a solid is changed to a liquid phase, the solid A. absorb energy B. release energy C. neither 5. When work is done by a system and no heat added to it, the temperature of the system A. Decrease B. Increase C. Remains unchanged 6. An inventor discovers a harmless and tasteless salt, which, when added to water changes its boiling point, the market value for this salt will be best if the salt A. lower the boiling point of water B. raises the boiling point of water C. either raises or lowers the boiling point, as the food would be cooked either way. 7. A good asorber of radiation is a A. good reflector B. good emitter of radiation C. poor emitter of radiation 8. The amount of energy ultimately converted to heat by light bulbs is about A. 30% B. 60% C. 15% D. 45% E. 100% 9. Steam burns are more dangerous than burns caused by boiling water becuase steam A. Gives the additional energy when it condenses B. Has more energy per kilogram than boiling water C. Both of these D. neither of these Answers for # 1 through #9 are D,A, B, A, A, B, B, E, C. please correct me thxs

Thank so much .. im goin to luv this forum

I need help with hw .. heres the question please correct me if i am rong Ice is put in a cooler in order to cool the contents. To speed up the cooling process, the ice can be A. Wrapped in newspaper B. Kept out of contact with the food C. crushed. D. Drained of Ie water periodicly. ANSWER: C. crushed. <-- pretty sure Crushed will have a larger surface area, therefore a larger area that can be cooled at once A volume of air has a temperature of 0degrees Celsius. An equal volume of air that is twice as hot has a temperature of A. 100degree Celsius B. 0degree Celsius C. 2degree Celsius * i think its this one not sure* D. 273degree Celsius ANSWER: B. 0degree Celsius, I thought of this as a math problem because of the key word "is" which means multiply .. so 0 times 2=0 Compared to a glass of ice water with ice in it, a glass of plain ice-cold water without ice on a warm day will warm up A. Faster * i think its this 1 not 100% sure* B. Slower C. In the same amount of time. ANSWER: C I think its in the same amount of time because even though both are not the same, they still warm up in the same rate. In the mountains, water boils at A. a lower temperature than at sea level B. Higher temperature than at sea level C. Same temperature as at sea level ANSWER: A Since the mountain is really high it takes a lower temperature? thats just a guess i am not sure. When a volume if air is compresed, its temperature A. Increase * im like 90% sure* B. Decrease C. Neither When a volume of air is compresed, its temperature A. Increase B. Decrease C. Neither ANSWER: A When volume increase temperature decrease but when volume is compressed temperature is increease? i think thats how it works If an object radiates more energy than it absorbs, it's A. temperature decreases B. Thermal energy decreases C. Both of these ANSWER: C I think when anything radiates more energy than it absorbs, it has something to do with both temperature decrease and thermal energy decrease The reason the sun's radiate energy is of shorter wave lenths than the Earth's is because the sun A. Has a higher temperature than Earth B. Has much more thermal energy C. is an energy source while the Earth is primily an energy reciever ANSWER: i am clueless rite here please help