Tag: science & technology

Hydrocyanic acid (HCN) is highly flammable and volatile, unlike the other common mineral acids listed which are corrosive but not combustible. HCN can form explosive mixtures with air and requires special handling precautions.

An android is specifically defined as a robot designed to look and act like a human. This distinguishes androids from general robots that may have any form or function. Option A describes multi-functional robots, Option B describes autonomous decision-making capability, and Option C is irrelevant to the definition.

Diamonds are formed from carbon (coal is primarily carbon) subjected to extreme heat and pressure over long periods deep within the Earth. This process transforms the carbon atoms into a crystalline structure. Graphite is also carbon but requires different conditions, while obsidian is volcanic glass.

The pistil is the female reproductive part of a flower, consisting of the stigma, style, and ovary. The stamen is the male part, while stem and petal are structural/support parts.

The Achilles tendon connects the calf muscles to the heel bone and is located in the lower leg/ankle region. It is the thickest tendon in the human body and enables walking, running, and jumping.

The chemical symbol for antimony is Sb, derived from its Latin name 'stibium'. Many element symbols come from their Latin names rather than English, which is why antimony uses Sb instead of An. Astatine (At) is a different element entirely, and Sg is seaborgium.

Radon's chemical symbol is Rn, following the standard pattern of taking the first two letters from the element's name. Rd, Ra (radium), and R are not valid symbols for radon. Noble gases like radon typically use this straightforward naming convention.

Strontium's symbol is Sr, taking the first letter and the second consonant. Sn is tin, Sm is samarium, and St is not an official element symbol. The symbol Sr clearly identifies strontium on the periodic table.

Promethium uses the symbol Pm, formed from the first letter and the 'm' sound in the middle. Pr is praseodymium, Pt is platinum, and Th is thorium - all different elements. Promethium is a radioactive lanthanide.