1) the object would change color (start to rust or just chnage color)
2) The new substance is ireversable (cant chnage back to original form)
3)theres gas formations (its can change into a gas property)
The answer is a. endothermic.
In endothermic reaction, as the name suggests, the reactants require energy absorption to form and complete the chemical reaction to form products.
And even if you don't know the answer, you can exclude all other answers by scientific logic and you will be left with the correct answer.
Hope this helps.
by angular momentum conservation we will have
angular momentum of child + angular momentum of merry go round = 0
angular momentum of child = mvR
m = mass of child
R = radius of child
v = speed = 2 m/s
now let's say moment of inertia of merry go round is I
so we will have


so merry go round will turn in opposite direction with above speed
A, it's better to take a break to let your body rejuvenate.
Metals are giant structures of atoms held together by metallic bonds. “Giant” implies that large but variable numbers of Atoms are involved - depending on the size of the bits of metal. most metals are close packed - that is, they fit as many items as possible into the available volume.