Consider the redox reaction below. Upper Z n (s) plus 2 upper H upper C l (a q) right arrow upper Z n upper C l subscript 2 (a q) plus upper H subscript 2 (g 0). Which half reaction correctly describes the oxidation that is taking place? Upper Z n superscript 2 plus (s) plus 2 e superscript minus (a q) right arrow upper Z n (s). Upper Z n (s) right arrow upper Z n superscript 2 plus (a q) plus 2 e superscript minus. 2 upper H superscript plus, plus 2 e superscript minus right arrow upper H subscript 2. Upper H subscript 2 plus 2 e superscript minus right arrow 2 upper H superscript plus.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied