The answer is A.
Reason:<span>The </span><span>frequency of </span><span>waves are determined by the amount of waves that pass a specific point in a certain period of time and Radio stations broadcast their signals at different frequencies so that the range of radio frequencies can be used by many stations.</span>
First c<span>alculate the mole fraction of each substance:
acetone: 2,88 mol </span>÷ (2,88 mol + 1,45 mol) = 0,665.
cyclohexane: 1,45 ÷ (2,88 mol + 1,45 mol) = 0,335.
Raoult's Law:
P(total) = P(acetone) · χ(acetone) + P(cyclohexane) · χ(cyclohexane).
P(total) = 229,5 torr · 0,665 + 97,6 torr · 0,335.
P(total) = 185,3 torr.
χ for acetone: 229,5 torr · 0,665 ÷ 185,3 torr = 0,823.
χ for cyclohexane: 97,6 torr · 0,335 ÷ 185,3 torr = 0,177.
Atoms are made of 3 types of subatomic particles ; protons, neutrons and electrons
protons and neutrons are located inside the nucleus and electrons are found in energy shells around the nucleus. Protons are positively charged, electrons are negatively charged and neutrons are neutral. elements in their ground state are neutral with equal amounts of protons and electrons.
Atomic number is the number of protons. atomic number is characteristic for the element.
atomic number of Be is 4 therefore Be has 4 protons
answer is B. 4
