Tag: science & technology

The River Thames flows through the city of London. It is the major waterway of London and the longest river entirely in England. The Yangtze is in China, Seine in France, and Danube flows through multiple European countries but not London.

The Hudson River flows through New York City. It separates Manhattan from New Jersey and is a major estuary. The Tagus is in Portugal/Iberia, Nile is in Africa, and Yangtze is in China.

The Nile River flows through Cairo, Egypt. It is the lifeline of Egypt and Cairo is situated on its banks. The Hudson is in USA, Yangtze in China, and Tagus in Portugal.

The River Seine flows through Paris. Many famous Paris landmarks like the Eiffel Tower and Notre Dame are situated along its banks. The Thames is in London, Tiber in Rome, and Tagus in Portugal/Spain.

The Tiber River (Tevere in Italian) flows through Rome and is the city's most famous river. The Tagus is in Spain/Portugal, the Danube flows through Eastern Europe, and the Hudson is in New York.

The Yangtze River (Yangtze Kiang/Yangtse Kiang/Yangtse Chang) flows through Nanjing in China. The Tagus is in Spain/Portugal, the Thames in London, and the Tiber in Rome.

Methane (CH4) is the simplest alkane, having just one carbon atom bonded to four hydrogen atoms. Alkanes are saturated hydrocarbons with only single bonds, and methane has the minimum possible structure, making option A correct.

An alkane with 9 carbon atoms is called nonane, making option E correct. The IUPAC naming system uses numerical prefixes (meth-1, eth-2, prop-3, but-4, pent-5, hex-6, hept-7, oct-8, non-9, dec-10) followed by '-ane' for alkanes.

Alkynes are hydrocarbons that contain at least one carbon-carbon triple bond, making option C correct. This triple bond (C≡C) is the defining characteristic that distinguishes alkynes from alkanes (single bonds) and alkenes (double bonds).

The IUPAC name for acetaldehyde is ethanal, making option D correct. Acetaldehyde has 2 carbon atoms (eth-), so it becomes 'ethanal' under IUPAC rules. The '-al' suffix indicates it's an aldehyde. Methanal is formaldehyde (1 carbon), while methanol and ethanol are alcohols.