Confined Spaces: Hazards, Risks, and Safety Measures
Confined Spaces: Definition and Examples
A confined space is any space with limited openings for entry and exit, where an employee can fully enter. These spaces often have unfavorable natural ventilation, allowing pollutants to accumulate, creating toxic, flammable, or oxygen-deficient atmospheres. Confined spaces are not designed for continuous human occupancy.
NIOSH Definition of Confined Space
The National Institute for Occupational Safety and Health (NIOSH) defines a confined space as any space
Read MoreKey Chemistry Concepts and Formulas
Conversions
- Celsius to Fahrenheit: F = (9/5) * C + 32
- Celsius to Kelvin: K = C + 273
Atomic Structure
- Atomic Mass: Protons + Neutrons (upper left symbol)
- Atomic Number: Protons (bottom left symbol)
Constants
- Planck’s Constant (h): 6.6260755 x 10-34 J*s
Photons
- Energy of a Photon: E = hv or E = hc / wavelength
Electronic Transitions
- Absorption: When energy is absorbed by the hydrogen atom, the electron is excited to a higher energy level or orbital.
- Emission: When the electron relaxes from a higher energy orbital
Chemical Bonds: Polarity, Metallic & Intermolecular Forces
Polar Covalent Bonds and Polarity
Polarization of Bonds: A polar bond forms when two atoms with different electronegativity come together. This results in partial charges appearing at the ends of the bond. A bond is more polarized the greater the difference in electronegativity between the two atoms. This difference indicates the percentage of ionic character in the covalent bond.
Polar Molecules
A diatomic molecule is polar if its bond is polarized. For a polyatomic molecule to have a molecular dipole
Read MoreAtomic Structure, Chemical Bonding, and Solutions
Elements and Atoms
An element is a pure substance that cannot be broken down into simpler substances.
An atom is the smallest part of an element that has all the properties of that element.
Atomic Structure
Atoms have a very dense center called the nucleus. The nucleus is made up of protons and neutrons.
- Protons are positively charged (+).
- Neutrons are neutral (no charge).
- Electrons are negatively charged (-).
You can tell how many protons an atom has by looking at the periodic table (the atomic number
Read MoreUnderstanding Metallurgy: Processes, Techniques, and Applications
Metallurgy: An Overview
Metallurgy is the science and technology of metals. Metals are electropositive, meaning they tend to lose electrons. They conduct heat and electricity, and possess a solid-state crystal structure where atoms are arranged in a regular network. Metals are generally isotropic, exhibiting identical properties in all directions.
A mineral is a naturally occurring substance with a consistent composition within a defined range. An ore is a mineral deposit with a concentration of a
Read MoreSilver Cation: Properties, Reactions, Health and Environmental Effects
Silver (Ag) is a white metal, malleable and ductile. It is insoluble in dilute hydrochloric and sulfuric acids but dissolves readily in nitric acid and concentrated sulfuric acid. Silver is almost always monovalent in its compounds, but divalent oxides, sulfur fluoride, and some coordination compounds containing divalent and trivalent silver are known. Although silver does not oxidize when heated, it can be oxidized chemically or electrolytically to form silver oxide or peroxide, a powerful oxidizing
Read More