Quantum Physics, Atomic Models, and Chemical Bonds
Quantum Physics and Atomic Models
Max Planck stated that bodies emit and absorb energy in discrete packets called energy quanta: E = hv.
Hertz observed that when metal electrodes are illuminated with ultraviolet light, they discharge. The emission of electrons from certain metals when exposed to light of a specific wavelength is called the photoelectric effect.
Bohr Model
- Electrons revolve around the nucleus in specific circular orbits without losing energy. These orbits are called stationary orbits.
Matter Properties, Changes, and Separation Methods
Chemistry: Matter and Its Properties
Chemistry is the science of matter, its properties, and the changes it undergoes. Matter is all around us; it has mass and occupies a volume, even if it is sometimes invisible.
Homogeneous and Heterogeneous Mixtures
- A homogeneous mixture, or solution, has the same composition at every point (e.g., sugar dissolved in water).
- A heterogeneous mixture does *not* have the same composition at every point, and its components are distinguishable.
States of Matter and Their
Read MoreEssential Chemistry Terms: Atomic Structure and Compounds
Essential Chemistry Terms
Here’s a breakdown of key chemistry terms related to atomic structure and chemical compounds:
- Aufbau Principle: The process for determining the electronic structure by filling energy levels of atoms.
- Electronic Configuration: The arrangement of electrons in the subshells and orbitals of an atom.
- Quantum: The smallest discrete quantity of energy that can be emitted or absorbed. A quantum of light energy is called a photon.
- Wave-Particle Duality: The concept that electrons exhibit
Essential Chemistry Terms and Definitions
Atom: The smallest particle of matter.
Understanding Matter: Properties, Composition, and Atomic Structure
Pure Substances and Mixtures
Pure substances are composed of particles that are identical.
- Simple Substances: These cannot be broken down into simpler substances by chemical methods. Their atoms are all the same (e.g., iron, gold, copper, chlorine).
- Composite Substances: These are formed by the union of two or more chemical elements in a fixed proportion. They can be separated into their constituent elements by simple chemical methods (e.g., water, sodium chloride).
Mixtures are combinations of two
Read MoreEnglish Learning Exercises: Greetings, Numbers, Verbs
Answer the Following Questions About Yourself
A. What’s your name?
My name is Jose Alberto Alvarez Olivo.
B. How are you?
I’m fine, thanks.
C. How old are you?
I am 23 years old.
D. Where are you from?
I am from the Dominican Republic.
E. Where do you live?
I live in San Francisco de Macoris.
Write 5 Formal or Informal Greetings in English
- A. Good afternoon, how are you?
- B. Good morning, how did you sleep?
- C. How are you doing?
- D. How’s your day going?
- E. Nice to meet you.