Chapter 2 - The Chemical Context Of Life

Three Main Questions
- What are organisms consist of?
Organisms are consist of matter. Matter is anything that has mass and take space. Its occurs in many forms such as: rocks, gases, metals,...
- What is an element?
Element is a substance that is impossible to brake down by chemical reaction. There are 92 elements that were discovered by scientists.
- What is element's properties depend on?
Element's properties are mainly depend on the structure of its atoms.

Five Facts
- The study of biology is somehow connected to chemistry.
- A compound is a substance consisting of two or more different elements combined in a fixed ratio.
- Isotopes are atoms with the same number of protons but different number of neutrons.
- Atom is consists of even smaller part called subatomic particles.
- There are two types of bond called: covalent bonds and ionic bonds.

Diagram The periodic table is the diagram that display the chemical elements. Each box contains information held about a certain element. The periodic table is arrange into several groups who have similar chemical properties. The number on top refers to the number of protons present in the atom. The letter represents the chemical formula of that atom. Finally the number at the bottom of the box is refers to the mass of an atom.

Summary
Chapter 2 is an introduces about some basic information of how chemistry simply apply throughout our study of life and biology. An element's properties is mostly depend on the structure of its atoms. There is an unit that even smaller than atom which is subatomic. Atom is made up of subatomic particles.
The number of protons in the nucleus of a atom is called atomic number. We can calculate the mass number by finding the sum of protons and neutrons. Isotopes are a different atomic forms of the element. Most of the atoms have the same numbers of protons. Chemical bonds are the result of two atoms staying close to each others and was held by attractions. There are two types of chemical bond called covalent bond and ionic bond.

Video
http://www.youtube.com/watch?v=ERy18NwemVc

10 Key Terms:
- Element: the substance that cannot be broken down to other substances by chemical reaction.
- Compound: a substance consisting of two or more different elements combined in a fixed ratio.
- Atom: the smallest unit of matter that still retains the properties of an element.
- Atomic number: the number of protons in the nucleus of an atom.
- Mass number: the sum of protons plus neutrons in the nucleus of an atom.
- Atomic mass: the total mass of an atom.
- Radioactive isotope: is one in which the nucleus decays spontaneously, giving off particles and energy.
- Isotope: one of several atomic forms of an element, each with the same number of protons but a different number of neutrons.
- Energy: the capacity to cause change for instance by doing work.
- Hydrogen bond: forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom.