C) sun:正确。氦(Helium)源自希腊语“ἥλιος (helios)”,意为“太阳”,因其首次在太阳光谱中被观测到而得名。D) earth:错误。氦与地球无直接关联,且命名源于太阳。选项中的逗号可能是排版错误,但内容错误。结论:正确答案为C选项“sun”,符合氦的命名由来。反馈 收藏
【题文】 Carbon is a chemical element which is present in organic compounds that make us organisms, plants as well as fossil. It is a vital component of the greenhouse gas CO2, the highest percentage of the global warming gas in the atmosphere. These Green House Gases (GIIGs) along with...
Uranium is a naturally occurring radioactive element, which has the atomic number of 92 and corresponds to the chemical symbol U in the periodic table. It belongs to a special group of elements called “actinides” — elements that were discovered relatively late in history. Like all other act...
Which element has the lowest electronegativity? ___. Which element has the second-highest electronegativity? ___. What types of atoms typically form ionic bonds? What is a property of metals? Give the symbol for each of the following elements. (a) lead (b) sodium (c) oxygen What are th...
(b) addition to the organic phase of a second extractant which can selectively retain the E2 element(s) in the organic phase during the next stage; (c) selective de-extraction of element(s) E1 from the organic phase with an aqueous solution able to withdraw the element(s) from the ...
Chemical elements can be named after minerals. Which element is named after a mineral containing iron? A. Manganese B. Magnesium C. Mercury D. Molybdenum 相关知识点: 试题来源: 解析 A。锰(Manganese)是以一种含有铁的矿物命名的。镁(Magnesium)、汞(Mercury)、钼(Molybdenum)都不是以含有铁的矿...
Chemical elements can be named after planets. Which element is named after Uranus? A. Uranium B. Platinum C. Potassium D. Phosphorus 相关知识点: 试题来源: 解析 A。铀(Uranium)是以天王星(Uranus)命名的。铂(Platinum)、钾(Potassium)、磷(Phosphorus)都不是以行星命名。
- The most commonly known liquid metal at room temperature is mercury. 4. Confirm the Chemical Symbol: - Mercury is represented by the chemical symbol Hg. 5. Conclusion: - Therefore, the metal that exists in a liquid state at room temperature is mercury (Hg). Final Answer:The metal w...
Which one of the following has the element name and symbol incorrectly matched? a) K, potassium b) Co, cobalt c) Fl, fluorine d) Ag, silver e) As, arsenic What is the chemical symbol for oxygen? K is the chemical symbol for which element? Hint: It doesn't start ...
Atomic Number:Atomic number of the element is equal to the number of protons present in the nucleus of the element which is denoted by symbolZ. The superscript presents on the left side of thesymbol of the element. Atomic radius: Atomic radius is the distanc...