Answer:
Explanation:
7) A block of wood
has a length of 10.2
cm, a width of 6 cm
and a height of 4.1
cm. The wood has
a total mass of 179
grams. What is the
volume of the
wood and what is
the density of the
wood?
volume = L XW XH=10.2 X 6 X4.1 =250.92cm^3
DENSITY = M/V = 179gm/250.92 cm^3
=0.713 gm/cm^3
Heat underneath the ground making its water boil
Explanation:
A change that does not cause any change in chemical composition of a substance is known as a physical change.
For example, mass, density, volume etc are all physical changes.
On the other hand, a change that brings change in chemical composition of a substance is known as chemical change.
For example, combustion, toxicity, reactivity etc are all chemical changes.
Hence, following statements are identified as chemical or physical changes as follows.
(a) Oxygen gas supports combustion : Chemical change
(b) Fertilizers help to increase agricultural production : Chemical change
(c) Water boils below
on top of a mountain : Physical change
(d) Lead is denser than aluminum : Physical change
(e) Uranium is a radioactive element : Chemical change