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
Answer:
d = 14.9 g/mL
Explanation:
Given data:
Mass of metal = 22.4 g
Volume of eater = 3.2 mL
Volume of water + metal = 4.7 mL
Density of metal = ?
Solution:
Volume of metal:
Volume of metal = volume of water+ metal - volume of water
Volume of metal = 4.7 mL - 3.2 mL
Volume of metal = 1.5 mL
Density of metal:
d = m/v
d = density
m = mass
v = volume
d = 22.4 g/ 1.5 mL
d = 14.9 g/mL
The answer is -ate:
If there are two similar, oxygen-containing ions, the ion with more oxygen atoms ends in -ate.
C. releases less energy than it uses