Chemistry - Central Science C1

Key Terms from the first chapter of the Chemistry book Central Science

Ag

Silver

Sb

Antimony

Sn

Tin

Pb

Lead

He

Helium

Pt

Platinum

Co

Cobalt

Br

Bromine

V

Vanadium

Hg

Mercury

Matter

Something that has mass and takes up space

Heterogeneous Mixture

Not uniform throughout

Homogeneous Mixture

Parametric composition (variable) and uniform throughout

Pure Substance

A sample of matter that has fixed composition (is not parametric, is uniquely categorized by its properties)

Compound Substance

A pure substance formed by more than one kind of atom

Element

A pure substance made of only one kind of atom

Physical properties

A characteristic of a pure substance that can be observed without changing it into another substance

Chemical properties

Characteristic that cannot be observed without altering the substance

Intensive properties

Does not depend on the amount of matter present (e.g. boiling temperature)

Extensive properties

Depend of the amount of matter present (e.g. mass and volume)

Physical Change

A change in a substance that does not involve a change in its composition

Chemical Changes (or Chemical Reaction)

A substance is transformed into a chemically different substance

Volatile

Lower boiling point relative to other substance

Distillation

A process that separates liquid mixtures based on their differing boiling points. Involves heating the mixture to vaporize the more volatile component, then cooling the vapor to condense it back into liquid form, thereby isolating the components of the mixture.

Chromatography

A technique that is used to separate the components of a mixture based on the tendency of each component to travel or be drawn across the surface of another material.

Density of Diamond

3.5 g/cm3, greater than water, smaller than zirconia

Diatomic Elements

H2, N2, O2, F2, Cl2, I2, Br2 (Have No Fear Of Ice Cold Beer)

Energy

The ability to do work

Potential Energy

Energy that is stored and held in readiness

Chemical Energy

A form of potential energy that is stored in chemical bonds between atoms

Electrostatic Energy

Potential energy that results from the interaction of charged particles

Breaking Chemical Bonds

Consumes energy (increasing potential energy)

Creating Chemical Bonds

Releases energy

Unit of Mass

kilogram (kg)

Liter

10e-3 m³

If no temperature reported, for density and volume, it should be assumed

25⁰C

Joule (J)

SI unit of energy (kg-m²/s²; [E_K] = [1/2mv²] = [m][v²]=kg-m²/s²)

calorie (cal)

4.184J. Historically known to be the amount of energy needed to raise temperature 1 gram of Water from 14.5 to 15.5 ⁰C, also known as 15-degree calorie or cal_{15}

Calorie (Cal)

Equal to 1kcal

Kelvin to Celcius

K = C + 273.15

10e18

exa (E)

10e15

peta (P)

10e12

tera (T)

10e9

giga (G)

10e6

mega (M)

10e-6

micro (μ)

10e-9

nano (n)

10e-12

pico (p)

10e-15

femto (f)

10e-18

atto (a)

Precision

The degree to which repeated measurements are consistent with each other.

Accuracy

The degree to which a measurement is close to the true value.

Standard Deviation

A statistical measure that quantifies the amount of variation or dispersion in a set of data values. It indicates how much individual data points differ from the mean.

68-95-99.7 rule (or empirical rule)

A statistical rule stating that for a normal distribution, approximately 68% of data points fall within one standard deviation, 95% within two, and 99.7% within three standard deviations from the mean.

Difference between 5000 and 5000.

The former has more significant digits than the latter. Indicating good accuracy.

Law of Constant Composition

States that the elemental composition of a pure compound is always the same.

Work

The energy transferred to or from an object via the application of force along a displacement

Work (formula)

W = F * D

Kinetic Energy (formula)

KE = 1/2 m v²

Gravitational Energy (formula)

GE = m g h

Solution

A homogeneous mixture of two or more substances, where one substance (the solute) is dissolved in another (the solvent)

Filtration

A physical separation process that removes solid particles from a liquid or gas using a filter medium that allows the fluid to pass through while retaining the solids.

Rhenium

Re

Tungsten

W

Caesium

Cs

Indium

In

Arsenic

As

Xenon

Xe

Krypton

Kr

Tellurium

Te

Germanium

Ge

Mohs Scale

A scale used to rank the hardness of minerals, ranging from 1 (talc) to 10 (diamond)

Zinc

Zn