Physical Science Chp. 2 Notes

Lesson 1
Atom: Atoms are the building blocks of life, they are very small.
Subatomic Particle: A particle that forms the structure of an atom.
Nucleus: The center point of an atom.
Electron Cloud: The area in which electrons float about in orbit.
Proton: A positively charged particle in the atom.
Electron: A negatively charged particle in the atom.
Neutron: A neutrally charged particle in the atom.
Orbital: The path in which an electron takes around the atom.
Element: A type of atom that cannot be broken down anymore.
Submicroscopic: Something too small to be seen through a microscope.
The Big Bang: A theory that the universe just appeared one day.

Lesson 2
Periodic Table: A table that organizes the elements by groups and rows.
Atomic Number: The atomic number on an element tells how many protons are in an atom of that element.

Lesson 3
Atomic Mass: The number of protons and neutrons added together is the atomic mass.
Isotopes: An element that shares the same amount of protons, but a different number of neutrons.
Stable Isotope: A non-radioactive isotope.
Unstable Isotope: A radioactive isotope.
Monoisotopic Isotope: An element with only one stable isotope.
Half-Life: A Half-Life is used to measure the rate an unstable isotope reaches half its mass from decay.
Isotopic Abundance: The ratio of which multiple isotopes occur in nature.
Mass Spectrometry: How isotopic abundance is measured.

Answer: All of them.
Answer: The number of neutrons is: Atomic mass – Atomic number = number of neutrons. The atomic mass is 40, and the atomic number is 18. 40 – 18 = 22.

Lesson 4
Ion: A charged atom.
Cation: Positively charged ion.
Anion: Negatively charged ion.
Molecules: Two of the same atoms in a bond together.
Compounds: Two or more different atoms in a bond together.
Monatomic Ions: An ion with only one atom.
Polyatomic Ions: More than one atom bonded together that has a charge.
Inert: A term to tell if a substance is or is not chemically reactive.

Lesson 5
Mixture: A substance that can be separated without causing changes in its chemical composition.
Pure Substance: A Pure substance contains only one kind of particle.
Chemical Bonds: Atoms in compounds are joined together with chemical bonds, There are two types of bonds.
Ionic Compounds: Ionic compounds are made with positively charged metals.
Ionic bonds: Cations and anions are bonded together by an ionic bond.
Covalent Compounds: Covalent compounds are made up of nonmetal atoms sharing electrons with covalent bonds.

Lesson 6
Ionic: A type of bond in molecules.
Covalent: Another type of bond in molecules.

Lesson 7
Non-Polar Covalent Bonds: A type of covalent bond, they occur between atoms with similar electronegativity, and electrons are shared evenly.
Polar Covalent Bonds: Another type of covalent bond, occurs between atoms with different electronegativity, and electrons are shared unevenly.

Answer: Ionic bonds are a type of chemical bond that occurs when electrons are transferred between atoms of opposite charge. Ionic bonds are made of ions, and the change in charge comes from one atom donating an electron to the other atom through that bond.

Answer: An ionic bond is a chemical bond that occurs when electrons are transferred between atoms of opposite charges. When the two atoms come together with an opposite and equal charge, they become neutral as a pair.

Answer: Electronegativity refers to the strength with which each atom pulls on shared electrons. Depending on the electronegativity of the atoms that make up the molecule, covalent bonds can be either polar or non-polar.