fourth grade science words

> Atomatic number of the elements 1st Period n = 1 Short period 2 Atomic number 1 and 2 2nd Period n = 2 Short period 8 Atomic number 3 to 10 3rd Period n = 3 Long period 8 Atomic number 11 to 18 4th Period n = 4 Long period 18 Atomic number 19 to 36 5th Peri..

Selenium (Se) - 'Seles' Greek name for the moonPlutonium (Pu) - Neptunium (Np) Uranium (U)Mercury was named after a planet but derives its symbol Hg from the Latin word 'Hydragyrum' meaning liquid sil..

The trivial names are the commonly used names of carbon compounds. They are derived mostly from the source of the compound e.g., the name of formic acid is derived from 'formicus' the Greek word meaning red ants. Names arrived in this way were ambiguous and repeatin..

Soil can be defined as the uppermost crust of earth mixed with organic material and in which animals and microorganisms live, and plants grow. The word soil is derived from a Latin word solum meaning ground. It is a stratified mixture of inorganic and organic materials, both of ..

Soil - Soil can be defined as the uppermost crust of earth mixed with organic material and in which animals and microorganisms live, and plants grow. The word soil is derived from a Latin word solum meaning ground. It is a stratified mixture of inorganic and organic materials, b..

Chemically the term alcohol refers to a group of organic compounds, having -OH group in their composition. But the word alcohol used by the common man refers to ethyl alcohol or ethanol. It has a variety of uses, especially as a solvent. But by far the greatest use of alcohol is in the f..

Reflection of Light - When a ray of light hits a surface, it bounces off or reflects and then reaches our eyes. This phenomenon by which a ray of light changes the direction of propagation when it strikes a boundary between different media through which it cannot pass is described as the reflection..

Introduction - The cells that make up our body are so small that you could fit over 200 of them on the full stop at the end of this sentence Before we plunge into the chapter, here are some interesting facts about cells. Read on... The word cell is derived from the Latin word ce..

Around (600 - 500 B.C) the 'Samkhya' philosophy was popular. It asserted that matter was made up of five 'bhutas' or elements consisting of akasa (sky or space), vayu (air), tejas (fire), ap (water) and kshiti (the Earth). These bhutas, besides sharing common properties like colour, smell, taste a..

Introduction - Appliances used in our day to day life are based on the principles of electricity and magnetism. Electricity is one of the most important sources of energy. Lights, fans, motors, radios and television are some common appliances which work on electricity. Historically, it was friction..