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A helioscope is an instrument used for observing the sun and sunspots. The helioscope was first used by Benedetto Castelli and refined by Galileo Galilei.

Examples of Fundamental Quantities ; Mass, kilogram, kg ; Electric Current, ampere, A ; Temperature, kelvin, K ; Amount of Substance, mole, Mol.

A process called fractional distillation is used in oil refineries to separate (as well as join or split) the various lengths of hydrocarbon chains to create different petroleum products from the different distillates.

The nucleus contains two types of subatomic particles, protons and neutrons. The protons have a positive electrical charge and the neutrons have no electrical charge. A third type of subatomic particle, electrons, move around the nucleus.

The mass number = number of neutrons + atomic number. number of neutrons = The mass number - atomic number. number of neutrons = 37 - 17 = 20

The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of other gases, too, such as carbon dioxide, neon, and hydrogen.

C \(\frac{69}{12}\) H \(\frac{15.3}{1}\) O \(\frac{30.7}{16}\) C = 5.75, H = 15.3, O = 1.92 C \(\frac{5.75}{1,92}\) H \(\frac{15.3}{1.92}\) O \(\frac{1.92}{1.92}\) C\(_3\)H\(_8\)O

Solid in gas mixture: Smoke, ice clouds, dust. Liquid in gas mixture: fog, mist, vapour and hair sprays. Gas in solid mixture: aerogel, Styrofoam.

A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions and OH- ions to generate water.

Alkaline gases are any gaseous compounds that form an alkali (or basic) solution with a pH greater than 7 when dissolved in water. Ammonia is the most common alkaline gas

Charles' law is a special case of the ideal gas law in which the pressure of a gas is constant. Charles's law defines the direct relationship between temperature and volume. GIVEN DATA: V\(_1\) = 29.5cm\(^3\), V\(_2\) = ? , T\(_1\) = 0ºc or 273k, T\(_2\) = 15ºc or 288k \(\frac{V_1}{T_1}\) = \(\frac{V_2}{T_2}\) V\(_2\) = \(\frac{V_1 x T_2}{T_1}\) → \(\frac{29.5 x 288}{273}\) V\(_2\) = 31.1cm\(^3\)

Partial pressure is found by Dalton's Law: Px = PTotal ( nx / nTotal ) where Px = partial pressure of gas x PTotal = total pressure of all gases nx = number of moles of gas x nTotal = number of moles of all gases Step 1 Find PTotal Standard pressure is 1 atm. Step 2 Add up the number of moles of the component gases to find nTotal nTotal = noxygen + nnitrogen nTotal = 100 + 900 nTotal =1000cm3 Step 3 Now you have all the information needed to plug the values into the equation and solve for Poxygen P-oxygen = PTotal ( n-oxygen / nTotal ) oxygen = 1 atm ( 100 / 1000 ) oxygen= 0.1atm

The method used to prepare a salt depend on: the solubility of the salt in water. the heat stability of the salt

If you add salt to water, you lower its freezing point as well as raise its boiling point.

Shells and subshells are filled in energy level order, so electrons will fill the 2p subshell before the 3s shell. And the x subshell before the y and z.