General Science and Technology

Isaac Newton (along with Gottfried Wilhelm Leibniz) is credited as the inventor of calculus. Newton developed his version of calculus in the mid-1660s, calling it 'the method of fluxions.' Option B correctly identifies Newton as one of the inventors of calculus.

The Nobel Prize is named after Alfred Nobel, the Swedish inventor who invented dynamite. Nobel established the prize in his will, using his fortune from the dynamite patent and other inventions. The other options are inventions of different scientists: nuclear energy involved many researchers, the microscope was developed by Antonie van Leeuwenhoek, and radio waves were discovered by Heinrich Hertz.

Water exists in liquid state at room temperature (typically 20-25°C or 68-77°F). This is because water's freezing point is 0°C and boiling point is 100°C at standard pressure. At room temperature, water is between these two phase transition points, so it remains liquid. The other options are incorrect because solids have fixed shapes, gases have no fixed volume, and plasma is an ionized high-energy state not found at room temperature.

Hygroscopic salts absorb moisture from the atmosphere without dissolving in it. Anhydrous salts are simply without water of crystallization, while hydrophilic refers to water-attracting substances more generally. Hydrophobic substances actually repel water.

Stalactites (hanging from cave ceilings) and stalagmites (rising from floors) form primarily from calcium carbonate deposited by mineral-rich groundwater. While some formations contain silica, calcium carbonate is the dominant material. Sodium and magnesium carbonates are not the main components.

Erosion is the process of topsoil and rock removal by natural forces like wind, water, or ice. Corrosion refers to chemical degradation of materials, not physical removal. Desalination removes salt from water, and detoxification eliminates toxic substances.

Daniel Gabriel Fahrenheit invented the mercury thermometer in 1714, revolutionizing accurate temperature measurement. Edison developed electric lighting systems, the Wright brothers pioneered powered flight, and Franklin conducted electricity experiments but didn't invent thermometers.

Phyla are the primary taxonomic divisions within the animal kingdom, grouping organisms by fundamental body plans and characteristics. Orders and families are narrower categories within phyla. Subphyla are subdivisions of phyla, not the major divisions.

Marble chips are primarily calcium carbonate (CaCO3). When hydrochloric acid (HCl) reacts with calcium carbonate, it produces calcium chloride, water, and carbon dioxide gas (CO2). Hydrogen gas is typically evolved when acids react with metals, not carbonates.

A magnifying glass uses a convex lens, which is thicker at the center and converges light rays to create magnified images. Concave lenses diverge light and produce reduced rather than magnified images. Plano-concave and plane glasses don't produce magnification.

Crop rotation alternates different crops seasonally to replenish soil nutrients and prevent depletion. Repeatedly growing the same crop drains specific nutrients from soil. While irrigation and tilling support plant growth, they don't maintain fertility like rotation does.

Gramineae (also known as Poaceae) is the scientific family name for all grasses, including cereals and bamboos. The other options are similar-sounding but incorrect spellings not used in botanical taxonomy. Grass family classification is fundamental to plant science.

Gmail is Google's free webmail service that also supports POP3 and IMAP email access. Miranda IM and Psi are instant messaging clients, not email services. iChat was Apple's instant messaging application (now discontinued). Gmail was launched in 2004 and revolutionized free email with its massive storage capacity.

Gmail does indeed stand for 'Google Mail.' In fact, in some countries (particularly Germany and the UK), the service was officially branded as 'Google Mail' due to trademark disputes over the 'Gmail' name. While Google has since reclaimed the Gmail name in most territories, 'Google Mail' remains a valid and historically accurate expansion of Gmail.