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...
A tilting unit tilts container (100) along forward tilting direction, so that the container is moved from rest position on support region to activation position. A securing element (10) secures the container at activation position, so that slippage of container is prevented.HEIDRICH, KLAUS...
Electron affinity is the enthalpy change when a mole of electrons is added to a mole of neutral atoms (in the gaseous phase). This will form a negative ion - an anion. Electron Gain Enthalpy When electrons are introduced in...
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 ...
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。
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...
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 symbol Z . The superscript presents on the left side of the symbol of the element. Atomic radius: Atomic radius is the ...
For each atomic symbol, give the name of the element: a) Be b) Ag c) Si d) C Use the periodic table to find the symbol or name of the following elements. What is the symbol and charge of the element with 31 protons, 39 neutrons, and 28 electrons? W...