究竟哪一個才是最具權(quán)威的世界大學(xué)排名？
關(guān)于大學(xué)排名信息不實(shí)早已不是鮮見的新聞，每一次各大世界大學(xué)排行榜一發(fā)布，總是會引發(fā)各路人士激烈的討論。有人樂于分享自己學(xué)校的好成績，也有人怒于聲討和質(zhì)疑排名的準(zhǔn)確性。那這五花八門的各大排行榜單中，...
IB DP Chemistry: HL復(fù)習(xí)筆記13.1.4 Catalytic & Magnetic Properties
Catalytic Properties Transition metals are often used as?catalysts?in the elemental form or as compounds The ability of transition metals to form more than one stable oxidation state means that the...
IB DP Chemistry: HL復(fù)習(xí)筆記13.1.3 Complex Ions
Complex Ions Transition element ions can form complexes which consist of a?central metal ion?and?ligands A ligand is a molecule or ion that forms a co-ordinate bond with a transition metal by donat...
認(rèn)可度相對較高的國際競賽有哪些？
許多學(xué)生一聽到比賽就感到非常害怕，所以今天我們將幫助你整理5個部分的10個比賽，非常適合進(jìn)入比賽，這些比賽有強(qiáng)大的認(rèn)可，在國際知名度和認(rèn)可度相對較高，可以說“性價(jià)比”超高了！認(rèn)可度相對較高的國際學(xué)術(shù)活動...
IB DP Chemistry: HL復(fù)習(xí)筆記13.1.2 Variable Oxidation States
Variable Oxidation States When transition elements forms ions they lose electrons from the?4s?subshell first This is because when the orbitals are occupied, the repulsion between electrons pushes t...
IB DP Chemistry: HL復(fù)習(xí)筆記13.1.1 Transition Elements
Transition Elements Transition metals are elements with an incomplete d-subshell or that can form at least one stable cation with an incomplete d-subshell This definition distinguishes them from d-...
IB DP Chemistry: HL復(fù)習(xí)筆記12.1.2 Ionisation Energy Trends
Trends Across a Period Ionisation energies show?periodicity?– a trend across a period of the Periodic Table As could be expected from their electron configuration, the group 1 metals have a relativ...
IB DP Chemistry: HL復(fù)習(xí)筆記12.1.1 Emission Spectra & First Ionisation Energy
Convergence Limits on an Emission Spectrum Emission Spectra Electrons move rapidly around the nucleus in energy shells Heat or electricity can be used to excite an electron to a higher main energy ...
IB DP Chemistry: HL復(fù)習(xí)筆記11.2.6 Analysing Graphs
Analysing Graphs The?gradient?of a graph can be found by: In the case of a straight line graph: using a triangle and the equation for a straight line In the case of a curve: drawing a?tangent?to th...
