Answer:
4.D. 2KJ
5.B. close to 0 degree celsius
Explanation:
heat absorbed= heat given out
100g * 4.2 * (x-0)= 400g * 4.2* ( 20-x) where x is the new temp reached
then x= 20
i.e. the temperature of ice increases to 5 degree celsius and the temperature of water decreases to 5 degree celsius .
hope it helps
The volume of eye drop fluid in a bottle is specified in milliliter, because in medical 1 drop=12ml
"Stored electrical energy is converted to mechanical energy" is the one energy conversion among the choices given in the question that <span>occurs when a battery powered car rolls across the floor. The correct option among all the options that are given in the question is the second option or option "B".</span>
Half-life means that the matter degrades by 50% at each interval. 48.2 days is 2 intervals.
So, it would go down by 50% in the first interval, making it 50g. Then it would go down by another 50% from there, making the final amount of undecayed thorium-234 25g.
Answer:
E) less than 7
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
pH scale generally runs from 1 to 14 where pH = 7 represents neutral medium, pH < 7 represents acidic medium and pH > 7 represents basic medium.
Strong acids dissociate completely and when they react with base they form a salt of weak base and strong acid.
For example, 
is a weak base and 
is the hydrochloric acid.
So,
<u>Thus, the salt is of weak base and strong acid which corresponds to pH less than 7.</u>
