Earth , weighing

Cavendish repeated the experiment 29 times and found that the Earth weighed 6 x 1021 (6 followed by 21 zeros) metric tons. The... 

This view is illustrated by Helmonts famous willow tree experiment. A small willow tree weighing five pounds was planted in a tub of earth weighing 200 pounds. For five years nothing was added to the soil but water. At the end of that time, the tree had grown to weigh more than 150... 

Objective 5 47. The earth weighs about 1x10 tons. Convert this to gigagrams. (There are 2000... 

Global warming of the oceans. The oceans on Earth weigh 1.37 X 10 kg [9]. If global warming caused the average ocean temperature to increase by 1 °C, what would be the enthalpy increase AH7... 

Beryllium, like its neighbours Li and B, is relatively unabundant in the earth s crust it occurs to the extent of about 2 ppm and is thus similar to Sn (2.1 ppm), Eu (2.1 ppm) and As (1.8 ppm). However, its occurrence as surface deposits of beryl in pegmatite rocks (which are the last portions of granite domes to crystallize) makes it readily accessible. Crystals as large as 1 m on edge and weighing up to 60 tonnes have been reported. World reserves in commercial deposits are about 4 million tonnes of contained Be and mined production in 1985-86 was USA... 

The precipitate was then mixed with diatomaceous earth, collected on a filter, and washed with water and extracted with two 100 ml portions of boiling benzene. The aqueous filtrate was extracted with 50 ml of benzene, the combined benzene extracts washed with water and evaporated to dryness under reduced pressure. The crystalline residue, MP 140° to 147°C, weighed 30.8 g. Recrystallization from a mixture of benzene and hexane gave 27.6 g (83%) of 2-chloro-10-(3-dimethylaminopropyl)-10-hydroxythiaxanthene, MP 152° to 154°C. Analytically pure material from another experiment melted at 153° to 154°C. 

A stone about the size of a softball weighs roughly a kilogram. How many moles of such stones would be needed to account for the entire mass of the Earth, about 6 X 10 grams ... 

Discussion. Some of the details of this method have already been given in Section 11.11(C), This procedure separates aluminium from beryllium, the alkaline earths, magnesium, and phosphate. For the gravimetric determination a 2 per cent or 5 per cent solution of oxine in 2M acetic add may be used 1 mL of the latter solution is suffident to predpitate 3 mg of aluminium. For practice in this determination, use about 0.40 g, accurately weighed, of aluminium ammonium sulphate. Dissolve it in 100 mL of water, heat to 70-80 °C, add the appropriate volume of the oxine reagent, and (if a precipitate has not already formed) slowly introduce 2M ammonium acetate solution until a precipitate just appears, heat to boiling, and then add 25 mL of 2M ammonium acetate solution dropwise and with constant stirring (to ensure complete predpitation). 

As shown in Fig. 2-58, a body entering the earth s atmosphere at 25,000 fps has a kinetic energy equivalent to 12,500 Btu/lb of vehicle mass. Assuming the vehicle weighs a ton, it possesses a thermal energy equivalent... 

A special technique was developed for rare-earth samples in which rapid hydration and carbonation occurred. The rare-earth oxalates were found to be more stable than the oxides and were used as sample material. In the rare-earth processing procedures that include an oxalate precipitate, the oxalate can be used as sample material. The advantages are that no diluent is required, weighing is eliminated, and recovery of the rare earths is simplified. 

Rocks brought back from the moon weighed more on Earth than they did on the moon because Earth has a greater —... 

A 50-g amount (in the case of powder tea, 25 g) of each minced and homogenized plant sample is weighed into a 500-mL flask with a ground stopper and 100 mL of water are added. After standing for 2 h, 150 mL of acetone are added and the flask is vigorously shaken with a shaker for 30 min. The mixture is Altered by suction through a Alter paper with a layer of diatomaceous earth 1-cm deep. The residue on the filter paper is returned to the flask and re-extracted with 100 mL of acetone by shaking for 10 min and the mixture is filtered. The combined filtrate in the round-bottom flask is concentrated to less than 100 mL under reduced pressure below 40 °C. 

The Darwin mission will not be carried out until the middle of the next decade. However, the COROT (Convection, Rotation and Planetary Transits) telescope was launched from the Baikonur cosmodrome in December 2006. The satellite, which weighs 630 kg, circles the Earth at a height of about 900 km in a polar orbit. The mission is planned to last 21/2 years, and more than 120,000 stars are to be observed. 

On the earth itself, however, hydrogen is not the most common I element it is only the tenth most common on the basis of weight, and only third in the number of atoms. Hydrogen, chemically combined with other elements, is found in huge quantities in coal. and petroleum, in clay and some minerals, and in all plant and animal matter. If you weigh 100 pounds, 10 pounds of you is hydrogen. 

Greenberg and Kingston [821,822] used a solid Chelex 100 resin to preconcentrate these elements from 100-500 ml of estuarine and seawater prior to their determination. A procedure is described for the preconcentration of 100 ml of estuarine and seawater into a solid sample using Chelex 100 resin. This solid sample weighs less than 0.5 g, and contains the transition metals and many other elements of interest, but is essentially free of alkali metals, alkaline earth metals, and halogens. 

Alkali and Alkaline Earth Metals are determined as sulphate. Weigh the substance in a quartz or platinum crucible, add a few drops of concentrated (for explosive or unstable substances use 30-50 per cent acid) sulphuric add and evaporate cautiously. Finally ignite at dull red heat. 

It is possible to identify several apparently disconnected themes which led ultimately to the analysis of the chemistry of living cells. Perhaps the first biochemical experiment in Europe may have been that of van Helmont (1579-1644), a physician with a profound interest in chemistry. He grew a willow tree in a weighed amount of earth, watered it for five years and then weighed the earth and the tree again. The... 

Therefore, 1 N is 9.81 times less force than this, which is equal to a mass of 102 g (1000/9.81). Putting it another way, a mass of 1 kg will not weigh 1 kg on the moon as the acceleration owing to gravity is only one-sixth of that on the earth. The 1 kg mass will weigh only 163 g. 

Cavendish s most famous experiment, performed when he was nearly 70, is often described as weighing the Earth. This description is a little misleading, because what he was actually trying to do was determine the Earth s density. In order to do this, he needed to calculate the Earth s mass, though that wasn t his primary goal. 

The fact had been noticed and recorded, during the middle ages, that the earth-like matter which remains when a metal is calcined is heavier than the metal itself From this fact, modem investigators of natural phenomena would draw the conclusion, that calcination of a metal is an addition of something to the metal, not a separation of the metal into different things. It seems impossible to us that a substance should be separated into portions, and one of these parts should weigh as much as, or more than, the whole. 

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