A. Oxygen B. Gold C. Water D. Helium 相关知识点: 试题来源: 解析 C。解析:化合物是由两种或两种以上不同元素组成的纯净物。水(H₂O)是由氢和氧两种元素组成的化合物。A选项氧气(O₂)是单质,由一种元素组成;B选项黄金(Au)是单质;D选项氦气(He)是单质,所以C正确。反馈...
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In chemistry, a compound is a substance made up of two or more different chemicalelementscombined in a fixed ratio. When the elements come together, they react with each other and form chemical bonds that are difficult to break. These bonds form as a result of sharing or exchangingelectronsbe...
The nucleus of ordinary hydrogen, i.e., the proton, is represented by 1H1, an alpha particle (a helium nucleus) is 2He4, the most common isotope of chlorine is 17Cl35, and the uranium isotope used in the atomic bomb is 92U235. Nuclear reactions involving changes in atomic number or ...
Although it was claimed that the balloons contained helium, additional research revealed that hydrogen or acetylene was used. The explosion was brought on by the balloons rubbing up against a lightbulb. Where Does Helium Come From? Natural gas resourcescontain the non-renewable compound helium, deriv...
Why is helium considered a noble gas? Why does the concept of antisymmetric wavefunctions not need to be considered for the hydrogen atom? Explain why Zr4+ ion exists? Explain John Dalton's experiment that led to his atomic theory.
"Blowing up a balloon with helium a hydrogen compound and-or a hot air balloon with heat what excludes air is the same as putting one with just air in it underwater. Less inside cannot stay." - Doug Moon "Substance in area taken is competitive weight argument. To weigh object is relati...
Answer to: A solution is a: A. homogeneous compound. B. heterogeneous mixture. C. heterogeneous compound. D. homogeneous mixture. By signing up,...
Others, such as helium, radium, aluminium, and bromine, were discovered in the nineteenth century. The most abundant elements found in the earth’s crust, in order of decreasing percentage, are oxygen, silicon, aluminium, and iron. Others present in amounts of 1% or more are calcium, ...