In this video segment, the ZOOM cast demonstrates how to use cabbage juice to find out if a solution is an acid or a base.

A development of the atomic molecular theory from the law of multiple proportions and law of definite proportions.

The Biology course is a first-year course in biology at the high school level and involves the scientific study of living organisms. The course considers the interactions among the vast number of organisms that inhabit planet Earth. It presents the basic form and function of these organisms, from cells to organ systems, from simple viruses to complex humans. It delves into interactions between organisms, and between an organism and its environment. It also looks into how biotechnology is used to improve our health and daily lives.

- Understand the form and function of microorganisms
- Understand the form and function of plants
- Understand the form and function of animals
- Understand the workings of human biological systems
- Understand biology as it relates to the Earth's environment

Students are introduced to the concept of different kinds of matter. Students create models of different substances to learn to identify the differences between elements, compounds, and mixtures. This lesson is developed so that teachers can use it with English as a Second Language students.

The topmost element in mathML is "math" element.

The story of how elements from lithium to uranium are created by stars is illustrated through animation and a hands-on periodic table in this video segment adapted from NOVA.

This is a lab activity where the students group the given elements as metals, nonmetals or metalloids.

What you did and didn't know about elements.

This resource from the AMERICAN EXPERIENCE Web site, which contains both an interactive activity and illustrated text, looks at the composition of different types of steel and their impact on technology.

The following information will help you understand the Periodic Table of the Isotopes.

Elements: Each element has a fixed number of positively charged protons in its nucleus and an equal number of electrons orbiting the nucleus. For example, hydrogen (H) has one proton and one electron, but lead (Pb) has 82 protons and 82 electrons. There are about 115 known elements of which 82 are naturally abundant.

Isotopes: The nucleus contains both protons and neutrons. An element has a fixed number of protons but may exist with various numbers of neutrons. The sum of the protons and neutrons is the mass number. For example, helium exists as 3He(2 protons and one neutron) or as 4He (2 protons and 2 neutrons). The two forms of helium are called isotopes of helium. Isotopes of an element have the same chemical properties but different weights. Some elements have many isomers. Tin (Sn) has about 38 known isotopes. ~

This activity is a guided inquiry laboratory in which students perform reactions involving metals and hydrochloric acid in order to determine their activity series.

Web page for the dissemination of information about nuclear data

This video segment adapted from NOVA explains the origin of the elements and how scientists use unique element profiles to identify supernova types.

A reference and instruction for scientists of all levels. What chemistry software package would be complete without a periodic table? The actual use of this applet in the classroom is quite simple. Simply click on the desired element and data as well as a graphical plot of electron configurations will be displayed. This particular version shows the electronic configuration of the element in the panel on the right. Future versions of this applet will show relative atomic sizes, electronegativities and other periodic trends, as well as extensive atomic data.

This interactive periodic table developed for Teachers' Domain provides detailed information about the chemical properties of elements and illustrates the electron configurations that determine those characteristics.

This downloadable periodic table of elements, produced for Teachers' Domain, provides easy, transportable access to a wealth of chemical information, including the oxidation state number of each element.

This essay, written for Teachers' Domain, describes the foresight and pattern recognition that Russian chemist Dmitri Mendeleyev used to develop the modern periodic table of elements.

This activity teaches students about the periodic table and how element properties can be predicted through periodic trends.

In this physics activity, students will review and investigate stability of the nucleus of various elements. They will then determine factors that affect the stability of the nucleus.