Chemical equations are to be balanced to be able to follow the law of conservation of mass where it says that mass cannot be created or destroyed. Reactions should be that the mass of the reactants is equal to the mass of the products.
It has to be D. the time needed to boil the water decreased
Answer:
D) atomic radii increase from top to bottom of a group
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Other options are incorrect because,
A) atomic radii increase from left to right across the period
Correct = atomic radii decreases from left to right across the period
B) ionization energy increases from top to bottom within a family
Correct = ionization energy decreases from top to bottom within a family
C) electronegativity decreases from left to right across a period
Correct = electronegativity increases from left to right across a period
Answer:
B: Physical Science
Explanation:
The answer is physical science because you need to know the laws of physics and chemistry to know how a car works. Physical sciences = the sciences concerned with the study of inanimate natural objects, including physics, chemistry, astronomy, and related subjects.
