Answer:
B
Explanation:
The warmer the water, the more space it takes up, and the lower its density.
1) Carbon dioxide is a gas, so when
is evolved in the reaction, it appears as bubbles. The gas released extinguishes the fire and it can turn lime water milky.

2) When
is released in a decomposition reaction we can identify by the strong pungent smell of the gas released.
3) Saturated citric acid can cause corrosion of the metal layers present in the pipes. So, before draining out any acid it is neutralized so that the pipes and other plumbing works do not get damaged leading to leaks in the drainage system.
"Work done by a constant force on an object is the product of the force and the distance moved by the object in the direction of the force" -textbook
There is work done ONLY if the direction of the force and the direction the item is moving are the same. In figure A, the direction of the force (the lifting) is upwards (defying gravity), and the book is moving upwards, so work is done. In figure B, the force is still moving upwards (the person is carrying the books) but the book is moving to the right, so there is NO work done.
an atom that has 18 protons, 18 neutrons and 20 neutrons. This atom has mass number of 38
mass number is calculated as number of protons + number on neutrons
therefore the mass number of the atom = 18+20= 38
Since the atom has a electronic configuration of 2.8.8,the atom cannot be negatively or positively charged because it is stable.
The atomic number of the atom is 18 since atomic number is equal to number of protons