Explanation

Bronze is an Alloy consisting primarily of copper, commonly with about 12-12.5% tin .

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RY 23-12-2022

Explanation

The intensity of an earthquake is measured by the Richter scale.

It quantifies the energy released.

It was developed in 1935.

The Richter scale is used in seismology, the study of earthquakes.

Explanation

Graphite is a crystalline form of the element carbon.

It consists of stacked layers of graphene.

Graphite occurs naturally and is the most stable form of carbon under standard conditions.

Explanation

Johan Gutenberg, a German inventor, is credited with inventing the movable-type printing press around 1440.

It revolutionized the production of books and the spread of knowledge in Europe.

Explanation

A myopic defect can be corrected by using a concave lens of suitable power. 

Myopia is a disease related to Eye

Myopia is a common vision condition in which we can see objects near to us clearly, but objects farther away are blurry.

Myopia means دورکی نظر کی کمزوری

Explanation

A convex lens has either one or both of its surfaces curving outwards, that is, wider divergence from the plan at the center.

These lenses are used to correct long-sightedness (hypermetropia).

Explanation

Explanation

Ernest Rutherford showed (1919) that nitrogen under alpha-particle bombardment ejects what appear to be hydrogen nuclei.

By 1920 Ernest Rutherford had accepted the hydrogen nucleus as an elementary particle, naming it proton.

while

Electron was discovered by J. J. Thomson in 1897.

Explanation

Studies show that it takes an average of 8 minutes and 20 seconds for sunlight to move from the sun to the earth.

Sunlight moves at the speed of light.

You can see that the distance of the sun from the earth = 149.6 x 106 km.

Photons emitted from the surface of the sun need to traverse the vacuum of the universe to reach our eyes.

Explanation

Radioactivity was discovered by Henri Becquerel in 1896

They discovered radioactivity proving that the uranium emitted radiation without an external source of energy such as the Sun

Marie Curie with her husband Pierre Curie, coined the term radioactivity 

in 1903, Henry Becquerel shared the Nobel Prize for Physics with Pierre and Marie Curie

Ernest Rutherford did many experiments studying the properties of radioactive decay (alpha, beta, and gamma)