Explanation

• Email stands for Electronic Mail.
• It is a method of sending and receiving digital messages through the internet.
• The term electronic mail has been used with its modern meaning since 1975.
• The shorter form E-mail became common around 1979.

Additional information:

Parts of a valid email address:

1. Email Prefix
2. Email Domain

Address: example@mail.com

1. example = Email Prefix
2. mail.com = Email Domain

Last verified on 16-06-2026

Explanation

• The instrument used to measure temperature is called a thermometer.
• A thermometer shows how hot or cold an object or place is.

Additional information:

• Barometer measures air pressure.
• Hygrometer measures humidity (moisture in air).

Last verified on 16-06-2026

Explanation

• The Sun is the ultimate and main source of energy on Earth.
• It provides energy through solar radiation (light and heat).
• All forms of energy on Earth directly or indirectly come from the Sun.
• It supports life, climate, and ecosystems on Earth.

This energy is then converted into various forms, such as:

• Thermal energy (heat)
• Kinetic energy (wind, water currents)
• Electrical energy (generated from solar panels)
• Chemical energy (fossil fuels, biomass)
• Biological energy (food chains, ecosystems)

Last verified on 16-06-2026

Explanation

• CFCs, carbon dioxide (CO₂), and methane (CH₄) are all greenhouse gases.
• Carbon dioxide traps heat in the atmosphere and increases temperature.
• Methane is a very strong greenhouse gas with high warming effect.
• CFCs also damage the ozone layer and act as greenhouse gases.

Last verified on 16-06-2026

Explanation

• GMO stands for Genetically Modified Organism.
• It refers to an organism whose genetic material (DNA) has been changed using genetic engineering techniques.
• GMOs are developed to improve traits such as disease resistance, increased production, or better quality.

Last verified on 16-06-2026

Explanation

• Mass and Length are base quantities in SI units.
• Length SI Unit: meter (m)
• Mass SI Unit: kilogram (kg)

Additional information:

Base Quantities in SI System:

• Time (second)
• Electric current (ampere)
• Temperature (kelvin)

Last verified on 16-06-2026

Explanation

• Lamp is not a form of energy.
• It is a device that produces light.
• Heat, sound, and light are all different forms of energy.
• Energy is the ability to do work or produce change.
• A lamp converts electrical energy into light energy.

Last verified on 16-06-2026

Explanation

(9)² - (8)² = ?

Method 1: Direct  

9² = 81, 8² = 64  

81 - 64 = 17

Method 2: Formula a² - b² = (a - b)(a + b)  

(9 - 8)(9 + 8) = 1 × 17 = 17

Last verified on 16-06-2026

Explanation

(4x + 2)(2x) means 2x multiplies both 4x and 2  

2x × 4x = 8x² and 2x × 2 = 4x  

Add them = 8x² + 4x

Last verified on 16-06-2026

Explanation

Factorize x² + x - 2  

We need 2 numbers that:  

1. Multiply to -2 (last term)  

2. Add to +1 (middle term coefficient)  

Those numbers are +2 and -1, because 2 × (-1) = -2 and 2 + (-1) = 1  

So split middle term: x² + 2x - 1x - 2  

Group: x(x + 2) - 1(x + 2)  

Take common: (x + 2)(x - 1)

Last verified on 16-06-2026