Chemistry.

37° C To convert between Fahrenheit and Celsius scales, use the formula, [°C] = ([°F], 32) × 5/9. Inserting 98.6oF for the [oF] term, you get 37oC as the answer. [°C] = (98.6°F, 32) × 5/9 [°C] = (66.6) × 5/9 [°C] = 37

0.0001672 kg Scientific notation is a way to write very large or very small numbers. This method of notation is useful to scientists when they are writing very large or very small numbers, so they don’t have to write so many zeroes. To convert from scientific notation to standard notation, look at the exponent: The value of the exponent tells you how many spaces to move the decimal. Since the value of the exponent in 1.672 × 10-4 is 4, this tells us we will need to move the decimal 4 spaces. The sign of the exponent tells you which direction we are going. A positive exponent tells us to move the decimal to the right. A negative decimal tells us to move the decimal to the left. Since the sign of the exponent in 1.672 × 10-4 is negative, this means we will be moving the decimal to the left. So, since the exponent is negative and has a value of 4, so we just need to move the decimal 4 places to the left to arrive at the answer, 0.0001672.

Mole The International System of Units (SI, abbreviated from the French Système international) is the modern form of the metric system and is the most widely used system of measurement in the world. It comprises a system of units of measurement built on seven base units, which are: Unit Symbol Quantity meter m length second s time kilogram kg mass ampere A electric current kelvin K temperature mole mol amount of substance candela cd luminous intensity (brightness) As you can see in the chart above, the SI Unit to measure the amount of a substance is the mole and is generally used to represent atoms. The kilogram is the SI base unit of mass, while a meter is the SI base unit of length. A gram is an SI unit of mass, but note that it is not a base unit. The base unit for mass is the kilogram.

Anion An ion is an atom with a net positive or negative charge due to an unequal number of protons and electrons. More electrons than protons = negatively charged ion (this is called an anion). More protons than electrons = positively charged ion (this is called a cation). When there are a same number of protons but a different number of neutrons, this is called an isotope.

Isotopes are atoms of the same element (same number of protons) with different numbers of neutrons. The number of protons defines the element. The number of electrons is not part of the isotope definition because electrons can be gained or lost (forming ions) independently of isotope identity. A neutral atom will have electrons equal to protons, but that is a property of charge neutrality, not of being an isotope. Isotopes can be stable or radioactive. Many radioactive isotopes undergo decay because an imbalanced neutron-to-proton ratio makes the nucleus unstable.

An element’s number of protons The atomic number of an element shows the number of protons located in the nucleus of the atom. The number of protons determines the identity of the atom. For example, if an atom has 6 protons, it is Carbon. Therefore, the atomic number for carbon is 6.

Sublimation The transition in the question involves going directly from ice (a solid) into steam (a gas), without going through a transition to a liquid first. This is called sublimation. Freezing is going from a liquid to a solid. Melting is from a solid to a liquid. Evaporation is from a liquid to a gas.

5 The pH scale is centered around a pH of 7, which is considered to be neutral. Values below 7 are considered to be acidic, while values greater than 7 are basic. Since 5 is less than 7, it is an acidic pH value.

A bond that shares one electron pair In covalent bonds, electrons are shared between two atoms. This differs from ionic bonds, where electrons are completely donated from one atom to another. In a single covalent bond, one electron pair is shared, while in a double covalent bond, two electron pairs are shared.

A substance that increases the rate of a chemical reaction A catalyst increases the rate of a chemical reaction by lowering the activation energy. A catalyst is not consumed in a chemical reaction and is regenerated after each reaction it catalyzes.

Ionic NaCl is an ionic compound, which consists of a metal (Na) and a nonmetal (Cl). In this type of compound, ionic bonds are formed between the two atoms where the metal completely donates its electrons to the nonmetal.

28.2 % In order to get this answer, we need to first divide the volume of benzene (59 mL) by the total volume of the solution ( 59 + 150 = 209 mL). 59 ÷ 209 = 0.282 We then multiply by 100 to convert the decimal in a percent 0.282 × 100 = 28.2%.

loss, gain In a redox reaction, oxidation is the loss of electrons, and reduction is the gain of electrons. OIL RIG: Oxidation Is Loss Reduction Is Gain

Nonpolar compound A dipole occurs when there is an unequal sharing of electrons between two atoms in a molecule. In the dipole, there will be both a partially, positive and a partially-negative side. The more electronegative atom will be on the partially-negative side since it will be able to attract more electrons to itself.

20 Amino acids, which contain an amine and a carboxylic acid, are needed by the body to produce proteins. There are 20 amino acids that the body needs for protein synthesis, and they are grouped into two categories: essential and non-essential.

2– Oxygen is part of the Group 16 of the periodic table and carries a 2- charge. This is because it prefers to gain two electrons to form a full octet to adopt the electron configuration of the closest noble gas (Neon).

(CH2O)n Carbohydrates are molecules that are made up of carbon, hydrogen, and oxygen. In the general formula, n can be any number between 3 and 8. (CH₄O)ₙ→ Incorrect ratio (1:4:1), too many hydrogens. C₆H₁₂O₆→ This is the specific formula for glucose (a monosaccharide), not the general formula for all carbohydrates. (CHO)ₙ→ Missing the proper hydrogen-to-oxygen ratio (should be 2:1).

The concentration of hydrogen ions pH is defined mathematically as -log[H+]. As you can see, it is a measure of the concentration of hydrogen ions. Although we use pH to determine the acidity of a solution, it does not give any indication as to the strength of an acid (that is what pka does).

Electron Beta particles are high-energy, high-speed electrons that are emitted from an atomic nucleus. Beta decay can also emit a positron, and this is called β+ decay.

AB → A + B A decomposition reaction occurs when a compound breaks apart to form its constituent atoms. It looks like this: AB → A + B A combustion reaction occurs when fuel and oxygen yield water and carbon dioxide. A + O2 → H2O + CO2 A single replacement reaction occurs when one element replaces another in a single compound. AB + C → AC + B A double replacement reaction (also called a metathesis reaction) occurs when the cations and anions switch between two reactants to form new products. AB + CD → AD + BC

Metallic bond Metallic bonds hold metal lattices together and are an intramolecular force. Other examples of intramolecular forces are covalent bonds and ionic bonds. The other options are intermolecular forces that determine how other molecules interact with one another. Hydrogen bonds, dispersion forces, and dipole-dipole interactions are all types of intermolecular forces. Intermolecular forces are the forces that act between molecules, influencing the physical properties of substances. Each of these forces acts between molecules, not within them, and thus they are classified as intermolecular forces. They play a crucial role in determining physical properties like boiling and melting points, solubility, and viscosity.

Liquid and gas Liquids and gases can spread out to adopt the shape of whatever container they are placed into. A solid has a definite shape, so it will remain in its original shape no matter what container it is placed into.

Reactants The reactants are the chemical species that are used to generate the products. Reactants are always on the left side of the reaction arrow, and products are always on the right side.

96 For a radioactive substance to decay from 128 kilograms to 16 kilograms, it must undergo 3 half-lives (128 → 64 → 32 → 16). When the half-life of a radioactive substance is 32 days, then 3 half-lives would equal 96 days (3 × 32 = 96).

It increases the likelihood of molecules encountering one another. Increased surface area increases the opportunity for reactants to collide with one another. The more surface area that something possesses, the more sites it has available to react. Activation energy lowered → true for a catalyst, but surface area increase alone doesn’t necessarily lower activation energy. Introduces charges → incorrect; surface area doesn’t add charges. Reduces precipitate → unrelated to surface area effect on reaction rate.