<h2>
Answer:</h2>
The magnesium ribbon, <u>D. It forms a material to cast the tool mark</u>.
<h2>
Explanation:</h2>
When a magnesium ribbon is burnt in the presence of oxygen it gives out strong light and heat is produced. Apart from it, it leads to the production of substance called as magnesium oxide which is formed as the product due to the reaction of magnesium with the oxygen present in the air.
Tool marks are the mark which is created by tools while using them. In order to identify or locate them castes made up of magnesium oxide is utilized. When this is pasted on the suspected area, the tool mark of the suspected tool gets pasted on it.
I believe it’s C ) chemical changes since chemical changes are usually permanent
I’m pretty sure it’s spine since all have spines!!
CH
3
C≡CH
2mole
HCl
A
CH
3
C(Cl)
2
CH
3
Heat
aq.KOH
B
CH
3
COCH
3
Answer:
Explanation:
<u>1) Data:</u>
a) [OH⁻] = 2.1 × 10⁻⁶ M . . . (the symbol g shown in the question is a typo)
b) pH = ?
<u>2) Formulae:</u>
<u>3) Solution:</u>
- pOH = log ( 1 / 2.1 × 10⁻⁶ ) = 5.7
- pH = 14 - pOH = 14 - 5.7 = 8.3
