bald-eagle

Bald eagles are very popular sea eagles in the US because they are the national birds of US. Bald eagles are not actually bald. The word bald is a modification of an old English word “balde” that means white. They are identified by their white head with a yellow beak. They are the largest raptors and sits on the top of the food chain.
bald-eagle

What do they look like?

Bald eagles are the largest raptors that weigh around 9-15 pounds. Females are bigger and heavier than the males. Bald eagles have brown colored feathers on their bodies. They have a white head, yellow beak, and white tail. They are about 3 feet long, but their wingspan is up to 6 feet wide.
bald-eagle-looking

Diet

Bald eagles are carnivores (meat eater). They hunt down smaller animals including fishes and birds for their food. They mostly hunt salmon fish, rabbits, and ducks etc.

Bald eagles are excellent hunters with very good eye sight. They fly high in the sky and watch for prey. When the prey is spotted, they dive very fast with a speed of 160 km/h towards it and catch it with their sharp talons.
bald-eagle-catching-food

Habitat

Bald eagles are found the 50 states of US. They prefer to live near lakes or oceans where they can find food easily. They make their nests in the trees near the oceans or lakes.

bald-eagle-nest

Conservation Status

Bald eagles are not endangered species in these days. However, in 1967, over-hunting had brought them near extinction. But thanks to the good conservation efforts and laws made to protect bald eagles. Their population has increased very much in 40 years.

They are now out of endangered species list and are placed in the least concerned species list.

Fun Facts

  • Bald eagles can fly to great heights up to 10,000 feet.
  • Bald eagle is the national symbol of US, and it is also on the seal of the president of US.
  • The nests of bald eagles can be at the depth of 13 feet and can weigh as much as 2,000 pounds.
silver-element

silver-symbol

  • Symbol: Ag
  • Atomic Number: 47
  • Atomic Weight: 107.8
  • Melting Point: 961 °C (1763 °F)
  • Boiling Point: 2162 °C (3924 °F)
  • Discovered by: Known since ancient time.

silver-elementSilver is one of the precious metals found in the Earth’s crust. It is very famous metal like gold and is known by almost every people living on the Earth. People have been using silver from thousands of years ago. They mostly used silver for making jewelry and artworks.

Silver is classified as a transitional element in the periodic table. It has 47 protons and 60 neutrons in its nucleus. Its symbol is ‘Ag’ which is derived from the Latin word “Argentum”.

Characteristics and Properties

  • Silver is a white metallic colored, lustrous, and soft metal.
  • It is the very good conductor of electricity; better than all the metals.
  • It is highly malleable and ductile metal, but lesser than gold.
  • It doesn’t react with air. It is corrosion resistant metal.

Uses

Silver has wide areas of usage. It has been used by humans from thousands of years ago. Let’s see some of its uses.

  • Silver is the very good conductor of electricity; it is used by electronic industries to build very efficient circuits.
  • It is used for medical purposes, e.g. used to fill cavities of teeth by dentists.
  • It is used for making jewelry.
  • Used for making long lasting batteries (these batteries are expensive).

Where is it found?

Silver is rare element relative to other elements. This rarity also makes it the precious metal. It is not a very reactive element, so it found in its pure form and also in some minerals, e.g. argentite. The major silver producing countries are China, Peru, and Mexico.

argentite
Argentite

Discovery

Silver is one of the elements that is known to mankind since ancient time. Archaeologists have found many artifacts from ruined cities that were 5000 years old. These artifacts are made of silver metal and its alloys.

ancient-silver-coin
Ancient silver coins

Fun Facts

  • Silver was once used for making coins. These coins were used as currency much like the nickel coins of today.
  • Silver was once the main ingredient for photography. Photographic plates were immersed in silver nitrate solution. (see invention of the camera for more information)
  • Silver is germicide, means it can kill bacteria. But, silver metal is not toxic for humans.
platinum-element

platinum-symbol

  • Symbol: Pt
  • Atomic Number: 78
  • Atomic Weight: 195
  • Melting Point: 1768 °C (3215 °F)
  • Boiling Point: 3825 °C (6917 °F)
  • Discovered by: South Americans

platinum-elementPlatinum is one of the most precious metals found on the Earth. It is more valuable and rare metal than silver and gold. It looks very pretty and shiny that attract people attention when used in jewelry.

Platinum is classified as a transition metal in the periodic table. It is located in 10th column and 3rd row of the periodic table. Its nucleus contains 78 protons and 117 neutrons.

Characteristics and Properties

  • Platinum is a silvery-white and shiny metal.
  • It is a very dense element.
  • It is highly malleable and ductile metal.
  • It has good catalytic properties.
  • It is corrosion resistant and rust free.

Uses

Platinum is a very useful element, but since it is very rare on the Earth its uses are limited by its supply. Some uses of platinum are:

  • Platinum is used as a form of currency; it has high value due to its rarity.
  • Due to its luster and corrosion resistant property, it is used for making jewelry.
    platinum-ring
  • It is used as a catalyst in many chemical reactions, e.g. Hydrogen-fuel cells.
  • It is used for medical purposes including dental work.
  • It is used by automobile industries.

Where is it found?

Platinum is very rare metal, which makes it difficult to find in the crust. Since platinum is not a reactive element, which makes it available in its pure form in nature. The largest producers of platinum are South Africa and Russia. South Africa supplies about 68% of total platinum produced in the world.

Discovery

Platinum was first found and used by the South Americans. They used to make jewelry and art from the platinum without knowing that it is entirely different metal from the silver.

Platinum was first discovered by William Hyde Wollaston. He was an English chemist who isolated the platinum to its pure elemental form. Platinum got its name from the Spanish language word “Platina”, means “silver”.

Facts

  • Platinum is 3rd densest metal found on the Earth.
  • It is the second most ductile metal after the gold.
  • The name platinum is often used with awards which are ranked higher.
  • The worldwide production of platinum is about 160 tons. Compare them with the production of gold, which is about 2500 tons each year.
oxygen-symbol

oxygen-symbol

  • Symbol: O
  • Atomic Number: 8
  • Atomic Weight: 16
  • Melting Point: -218 °C (-361 °F)
  • Boiling Point: -183 °C (-297 °F)
  • Discovered by: W Scheele and Joseph Priestly independent of each other.

Oxygen is a vital element for all the living things on Earth. Almost all the living things need the oxygen to survive and stay alive (except few). Oxygen has transformed our Earth from deserted planet to a green planet.

It is the most abundant element in the human body and 3rd most abundant element in the universe.
oxygen-atom

Characteristics and Properties

  • Oxygen is a diatomic, colorless, and odorless gas under normal conditions.
  • Oxygen is a reactive gas, it easily reacts with iron and other metals to make them rusty.
  • It can dissolve in the water easily. Marine life is dependent on the dissolved oxygen in the water.

Uses

Oxygen is used by animals and plants for respiration. Besides respiration, it has a lot of other uses in industrial, military, and medical applications. Some uses of oxygen are:

  • It is used by NASA in the rockets to efficiently burn the fuel.
  • It is used for breathing underwater and in space.
  • Hospitals use oxygen tanks to supply oxygen to the patients.
  • It is used in the production of plastics, water filtration, and extraction of metal from their ores.

Where is it found?

As you know, oxygen is freely available in the atmosphere that we breathe. Our atmosphere contains about 21% oxygen. The upper atmosphere has a layer of ozone (triatomic oxygen) that protect us from cancer causing rays of the Sun.

atmosphere-composition
Atmosphere Composition

Besides the atmosphere, oxygen is the major constituent of water by weight. All the water you see in the oceans and the water that you drink is made of hydrogen and oxygen (H2O).
ocean

So is that over? No!

The sand that you walk on is compound called silicon dioxide. It has oxygen as a major constituent by the number of atoms.
sand-dune

So that means, we humans are breathing-in, stepping-on, and drinking the oxygen and its compounds from our beginning. Wow! What a miraculous element.

Discovery

Oxygen was known to man from early time because human have been breathing oxygen and burning fire for food and heat. But, it was considered as a separate element when C.W. Scheele discovered a gas that increased the burning rate of fire. He named this gas “Fire air” due to increased burning of fire. But, Scheele was unable to publish research.

Another British scientist named Joseph Priestley discovered the oxygen independently, without knowing about the Scheele’s discovery.

Facts

  • The liquid form of oxygen has the blue
  • Our Earth has the highest percentage of oxygen in the solar system.
  • The most abundant element in our body is oxygen.
  • The main oxygen producers are plants. They produce oxygen in a process called photosynthesis.
nitrogen-symbol

nitrogen-symbol

  • Symbol: N
  • Atomic Number: 7
  • Atomic Weight: 14
  • Melting Point: -210 °C (-346 °F)
  • Boiling Point: -195 °C (-320 °F)
  • Discovered by: Daniel Rutherford

Nitrogen is a gas with 7 protons and 7 neutrons in its nucleus. It is the major building block of our atmosphere. Our atmosphere is the mixture 21% oxygen, 78.1% Nitrogen, and 0.9% other gases. Nitrogen is also an essential element for the life, it available in every living thing including humans. Our DNA also contains nitrogen atoms.
nitrogen-atom

Characteristics and Properties

  • Nitrogen is a colorless and odorless gas.
  • It is non-metal diatomic gas with an electronegativity of 3.0.
  • It is almost inert gas in nature. However, it can react with other elements if the conditions are right.

Uses

Nitrogen is widely used in the manufacturing of many items. Some of its uses are given below:

  • The majority of the nitrogen is used to make ammonia.
  • It is used to produce nitrogen fertilizer and nitric acid.
  • It is used to provide the inert atmosphere for some electrical circuits, experimental environment, and explosive liquid tanks.
  • It is also used in the liquid state to super cool the things.

Where is it found?

Nitrogen is a gas that is freely and abundantly available in the atmosphere. Our atmosphere is composed of about 78.1% Nitrogen. Industries use fractional distillation method to separate the nitrogen from oxygen, water vapors, and other gases. There are many compounds of nitrogen found on the earth from which we can extract nitrogen, but getting nitrogen from air is easy.

atmosphere-composition
Atmosphere Composition

Discovery

Daniel Rutherford in 1772 was performing an experiment on the air. In that experiments, he found that there was a gas other than oxygen in the air that didn’t support the burning. He named that gas “noxious gas”. Nitrogen got its official name in 1790.

Facts

  • Titan is the moon of planet Saturn whose atmosphere is made of about 98% Nitrogen.
  • Nitrous oxide, also known as laughing gas is made with nitrogen. It is used by dentists for some dental procedures. It is called laughing gas because it makes some people laugh.
  • Nitrogen is used in the manufacturing of dynamite (an explosive).
  • Nitrogen is the 7th most abundant element in the universe.
  • The human body contains about 3% Nitrogen.