However <em>trans</em>-2-Butene does not give a characteristic peak in 1620-1680 cm⁻¹ region but still the presence of carbon double bond carbon can be detected by detecting following peaks in IR Spectrum.
1) 3010-3100 cm⁻¹:
As in trans-2-Butene a hydrogen atoms ate attached to sp² hybridized carbon, therefore the stretching of =C-H (C-H) bond will give a peak of medium intensity in the range of 3010-3100 cm⁻¹.
2) 675-1000 cm⁻¹:
Another peak which is given by the bending of =C-H (C-H) bond with strong intensity will appear in the range of 675-1000 cm⁻¹.
1789 -- raité élémentaire de chimie is a textbook written by Antoine Lavoisier published in 1789 and translated into English by Robert Kerr in 1790 under the title Elements of Chemistry
Answer:
element
Explanation:
we know that helium is a pure substance although helium atoms are sometimes mixed with their isotopes it is still the same element. since there is no other element combined with helium this makes it an element.
False.
Hope this helps, Good luck on the assignment.
Explanation:
When magnesium metal burns is heated i the air it forms magnesium oxide.The balanced chemical reaction is given as:

2 moles of magnesium metal when reacts with 1 moles of oxygen it gives 2 moles of magnesium oxide which is white in color.
Some times along with formation of magnesium oxide small amount of magnesium nitride also produced due to which magnesium oxide appears grey in color .The balanced chemical reaction is given as:

3 moles of magnesium combines with 1 mol of nitrogen gas to to give 1 mol of magnesium nitride.