The information shows the masses after the compounds are balanced. 2MgO + 2Cl2 → 2MgCl2 + O2

85g + 156g → 188g + ?

If the following materials are used during the reaction of magnesium, oxygen, and chlorine, what mass oxygen would we expect to see after the reaction and why?

A.
53g of O2, because all mass must be conserved.

B.
241g of O2, because all mass must be conserved.

C.
42.5g of O2, because all mass must be conserved, it would be half of the compound MgO in the products.

D.
106g of O2, because all mass must be conserved, it would be double the compound MgO in the products.

Apositive point charge q is fixed on a very large horizontal frictionless tabletop. a second positive point charge q is released from rest near the stationary charge and is free to move. which statement best describes the motion of q after it is released? assume q stays on the table

The frequency of vibrations of a vibrating violin string is given by f = 1 2l t ρ where l is the length of the string, t is its tension, and ρ is its linear density.† (a) find the rate of change of the frequency with respect to the following. (i) the length (when t and ρ are constant) (ii) the tension (when l and ρ are constant) (iii) the linear density (when l and t are constant) (b) the pitch of a note (how high or low the note sounds) is determined by the frequency f. (the higher the frequency, the higher the pitch.) use the signs of the derivatives in part (a) to determine what happens to the pitch of a note for the following. (i) when the effective length of a string is decreased by placing a finger on the string so a shorter portion of the string vibrates df dl 0 and l is ⇒ f is ⇒ (ii) when the tension is increased by turning a tuning peg df dt 0 and t is ⇒ f is ⇒ (iii) when the linear density is increased by switching to another string df dρ 0 and ρ is ⇒ f is ⇒

During which interval are the persons represented by the graph not moving? a) 0 to 0.5 hrs b) 1.5 to 2 hrs c) 2 to 2.5 hrs d) 4.5 to 5 hrs