# Science

Science

An atom contains protons, neutrons and electrons. Out of these particles, only protons and neutrons add to the mass of the atom, since electrons are relatively massless (they have very little mass...

Latest answer posted May 1, 2016 9:10 am UTC

Science

Both the lithosphere and asthenosphere are part of Earth and are made of similar material. Lithosphere is made up of Earth's outermost layer, the crust, and the uppermost portion of the mantle. In...

Latest answer posted March 19, 2016 12:41 pm UTC

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Plants, or members of the kingdom Plantae, share several characteristics. Most importantly, from the point of view of life on Earth, they are photosynthetic autotrophs: they make their own food...

Latest answer posted February 7, 2018 9:41 am UTC

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Temperature is a measurement of the average kinetic energy of the molecules in an object or a system. Kinetic energy is the energy that an object has because of its motion. The molecules in a...

Latest answer posted November 23, 2015 9:21 pm UTC

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Helpful bacteria: E. Coli are found in the intestines of humans and aid in digestion. Streptomyces is used in making antibiotics. Rhizobium are helpful bacteria found in the soil. They convert...

Latest answer posted April 10, 2010 1:03 pm UTC

Science

The short answer is diffusion. According to kinetic molecular theory, all particles of all substances are in constant motion as long as the temperature is above absolute zero. In solids, the motion...

Latest answer posted August 31, 2010 6:10 am UTC

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Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. Pure ethanol freezes at -115 degrees C, while mercury...

Latest answer posted November 22, 2015 8:16 am UTC

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A cyst is a small sac that is filled with fluid, gas, or other material and are usually benign. They are very common and can be found just about anywhere on the body. They are usually very small...

Latest answer posted August 17, 2010 1:17 am UTC

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Glucose does not dissociate when dissolved in water. In comparison, a substance like sodium chloride, dissociates into sodium and chloride ions when mixed with water. And the chemical equation for...

Latest answer posted February 9, 2016 2:39 pm UTC

Science

Propene reacts with water in the presence of a dilute, strong acid to produce propanol. The dilute, strong acid does not take place in the reaction itself. ~C_3H_6 + ~H_2O harr~C_3H_7OH The...

Latest answer posted March 26, 2016 10:57 pm UTC

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Ionic compounds are two or more ions held together by attraction. An example of an ionic compound is table salt. It consists of positive sodium ions and negative chloride ions. It is a crystal that...

Latest answer posted March 17, 2010 3:56 am UTC

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Analytical chemistry is the branch of chemistry that focuses on the identification and quantification of chemical compounds. It is divided into two major areas: the classical methods and the...

Latest answer posted January 9, 2016 12:55 pm UTC

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To calculate the percentage of oxygen in aluminum sulfate, Al_2(SO_4)_3 , we need to determine the molar mass of this salt. The atomic masses of aluminum (Al), sulfur (S) and oxygen (O) are 27,...

Latest answer posted January 13, 2016 10:42 am UTC

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A physical change does not accompany any change in composition of the material. For example, the melting of wax is not a change in composition, as it still stays wax and hence is a physical change....

Latest answer posted November 18, 2015 2:15 pm UTC

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The sperm cell must be propelled to the egg cell so that fertilization can occur. For organisms that live in water, the sperm will use their flagella to swim through the aquatic environment to the...

Latest answer posted March 23, 2016 12:22 am UTC

Science

At STP (standard temperature and pressure), an ideal gas occupies 22.4 liters per mole. Here we have 48 g of oxygen gas or O2, each molecule of which consists of two atoms of the oxygen element....

Latest answer posted May 2, 2016 4:07 pm UTC

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The easiest way to balance any combustion equation is to first write the general form. In a combustion reaction the products are always carbon dioxide (CO2) and water (HOH) and the reactants are...

Latest answer posted June 16, 2011 10:41 am UTC

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For a lens the relation between object distance, image distance and the focal length is given by 1/Do + 1/Di = 1/f, where Do is the object distance, Di is the image distance and f is the focal...

Latest answer posted April 20, 2012 2:41 pm UTC

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All of the living organisms within an ecosystem comprise a living community. Within the living community are feeding relationships that are known as food chains. However, usually there are several...

Latest answer posted January 30, 2016 4:37 pm UTC

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Polar compounds are compounds that have slight charges (slightly positive and slightly negative) within the compound. The slight charges are due to electronegativity differences of .3 to 1.4....

Latest answer posted November 19, 2015 1:49 am UTC

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Atoms, elements, compounds, and mixtures are all forms of matter. Matter is defined as anything that has mass and volume. Atoms, elements, and compounds are all pure substances. A pure substance is...

Latest answer posted February 28, 2016 12:54 pm UTC

Science

There are multiple questions being asked here. The following answer will focus on the first two questions as they are quite closely related. Meiosis is a process of reduction division. Students are...

Latest answer posted February 10, 2020 3:57 pm UTC

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Male bees do have a penis. When a male bee or drone mates with the female queen bee, its penis which is located internally is everted which means is turned inside-out during the process of mating...

Latest answer posted September 7, 2016 12:25 pm UTC

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There are two ways to solve this question. Since the sulfuric acid solution is made from a stock solution, the number of moles of sulfuric acid remains the same. In other words, the number of...

Latest answer posted April 6, 2016 12:07 am UTC

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Since 1 M solution is more concentrated than 0.25 M solution, we will have to dilute the higher strength solution (with distilled water) to obtain a lower strength solution. The following equation...

Latest answer posted February 8, 2016 11:45 pm UTC

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In a neutralization reaction, you have the addition of an acid with a base. Acids produce a hydrogen ion (H+), while bases produce a hydroxide ion (OH-). When you add an acid to a base, you get...

Latest answer posted February 15, 2012 2:57 am UTC

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We are talking about Na2CO3. This compound is called sodium carbonate. It is also sometimes referred to as soda ash. It dissolves in water in two different stages. The first dissociation stage...

Latest answer posted October 14, 2012 3:26 am UTC

Science

Assume H=height for dropped roll (roll 2) (to be determined), h=height for unrolled roll (roll 1) = 0.915m , r = inner radius = 0.0225m , R = outer radius = 0.0525m, M = mass of unrolled roll =...

Latest answer posted March 3, 2015 1:19 am UTC

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To boil a given quantity of water, we need to supply some heat to it. The amount of heat needed to increase the temperature of any substance is dependent on the mass of the substance, its specific...

Latest answer posted May 1, 2016 3:43 am UTC

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Matter is composed of particles. Particles are composed of one or more type of atom. Changes in Matter Physical Change: Physical change occurs when the particles of a substance become rearranged,...

Latest answer posted May 15, 2016 4:23 pm UTC

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Ethanol is a chemical compound made up of carbon, hydrogen and oxygen atoms. The chemical formula of ethanol is CH_3CH_2OH . When ethanol is burnt, it reacts with oxygen and produces water and...

Latest answer posted September 29, 2015 3:10 am UTC

Science

Hagar, I've always taught this as four steps, but I found this at answers.com and am copy pasting it here to help you out: 1. Understand the Problem2. Collect Information3. Form a Hypothesis4....

Latest answer posted July 16, 2011 3:49 am UTC

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Mg(s) + HCl (aq) ----> ? In answering this kind of reaction, first we have to identify which among the elements have the tendency to form another compound. -->Mg and Cl can form another...

Latest answer posted October 17, 2012 12:31 pm UTC

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A water molecule is not linear because of the electron structure of the oxygen atoms in the water molecules. Oxygen has 6 valence electrons in the second energy level. Its configuration is 1s2 2s2...

Latest answer posted September 25, 2011 9:19 am UTC

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Water is a liquid and its solid form is known as ice. When the water converts from the liquid phase (that is, water) to the solid phase (that is, ice), the process is known as freezing. Water...

Latest answer posted May 14, 2016 1:53 pm UTC

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When silver nitrate and potassium phosphate are combined, they form a double replacement reaction. In a double replacement reaction, the ions 'switch partners.' The balanced chemical reaction...

Latest answer posted April 6, 2016 2:08 am UTC

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Land transport: Takes place on land, using trucks, buses, trains, smaller vehicles like cars, etc. May also involves transport of liquids/gases through pipes. Commonly preferred for smaller...

Latest answer posted July 7, 2015 2:46 pm UTC

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Empirical formula gives us ratio of the number of atoms in a compound. In this case we only know that ratio of carbon atoms to hydrogen atoms is 1:2 but we don't know the exact number of atoms in...

Latest answer posted April 23, 2015 9:00 pm UTC

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Thermal capacity, also referred to as heat capacity, is the amount of heat required to change the temperature of an object by a certain degree. On the other hand, specific heat capacity, also...

Latest answer posted May 12, 2013 6:08 am UTC

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Hurricanes may lose strength over land because of cool temperatures, a lack of moisture, and/or friction. Hurricanes form over low pressure regions with warm temperatures over large bodies of...

Latest answer posted February 10, 2016 1:45 pm UTC

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The flow of electric current occurs because we have a high potential of electrons gathered at the positive terminal and a low potential of electrons at the negative terminal. It doesn't have so...

Latest answer posted March 31, 2012 12:28 am UTC

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Adolescence is the transitional period from childhood to adulthood. Determining when adolescence begins or ends is done mostly by individual development. Physically, boys are expected to realize...

Latest answer posted May 26, 2016 3:02 pm UTC

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Freezing refers to the phase change from liquid to solid phase. In this case, we are discussing the freezing of water. Water freezes at 0 degrees Celsius. Since no other information is given, let...

Latest answer posted May 14, 2016 12:05 am UTC

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In order to do this calculation we first need to understand the concept of the mole. Just as a "dozen" of something means 12 items, or a "pair" means 2, in chemistry a "mole" of something means you...

Latest answer posted May 8, 2012 9:27 pm UTC

Science

The terms covalent and molecular are often used interchangeably to describe the same type of substance. However, there is a distinction between the two. The term covalent refers to a type of...

Latest answer posted February 6, 2016 10:38 pm UTC

Science

The natural frequency of oscillation of a mass m attached to a spring with spring constant k is given by f = (1/2*pi)*sqrt(k/m). When a mass of 21 g is attached to a certain spring, it makes 18...

Latest answer posted February 11, 2012 11:05 am UTC

Science

Given Mass of Oxygen = 16 gm And STP condition that is .... P (Pressure) = 101.3 kpa R (gas constant) = 8.314 Lkpa/k mol T (absolute temperature) = 27. k V (volume) = ? n (mole) = mass / molar mass...

Latest answer posted June 23, 2012 12:01 pm UTC

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Prokaryotes can be divided into microorganisms called bacteria and archaea. Four differences between bacteria and archaea include: 1. Bacterial cell walls have peptidoglycan (mesh-like structure...

Latest answer posted October 13, 2011 12:11 pm UTC

Science

Short and long loop feedback generally refers to the hypothalamic-pituitary system of hormones. This system relies on a small cascade. First, the hypothalamus recognizes something in the body that...

Latest answer posted March 16, 2012 9:09 pm UTC