Answer:
d. 75 protons, 110 neutrons
Explanation:
In an isotope, the number next to the number of the atom is the mass number (Protons + neutrons). Rhenium has as atomic number 75, that means Rhenium has <em>75 protons</em>. As atomic mass, 185, is the sum of protons and neutrons, number of neutrons is:
185 - 75 = <em>110 neutrons</em>
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Thus, right answer is:
<em>d. 75 protons, 110 neutrons
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Answer:
6 mins
Explanation:
The time taken for Ar to effuse can be obtained as follow:
Time for Br₂ (t₁) = 12 mins
Molar mass of Br₂ (M₁) = 2 × 80 = 160 g/mol
Molar mass of Ar (M₂) = 40 g/mol
Time for Ar (t₂) =?
t₂/t₁= √(M₂/M₁)
t₂ / 12 = √(40/160)
Cross multiply
t₂ = 12 × √(40/160)
t₂ = 12 × 0.5
t₂ = 6 mins
Therefore, it will take 6 mins for the same amount of Ar to effused out.
Answer:
A
Explanation:
Hydrocarbons with short chain lengths are more volatile than those with longer chains. A practical example of this can be seen in the first few members of the alkane series. They are mostly gaseous in nature and this is quite a contrast to the next few members which are solid in nature.
As we move down the group, we can see that there is an increase in the number of solids. Hence, as we go down the group we can see a relative increase in order and thus we expect more stability at room temperature compared to the volatility of the shorter chain
Carbon can form a wide variety of organic compounds because:
Each carbon atom covalently bonds with toms of carbon, hydrogen oxygen, and nitrogen
A carbon atom can have 4 single valence electrons around it. This allows it to form covalent bonds with many different atoms.
Answer:
Chemical reactivity increases down a group and decreases from left to right of a period.
Explanation:
The higher the ionization energy is, the lower the reactivity is. Since the ionization energy is highest in the top right corner of the periodic table, we can assume that the most reactive elements are in the opposite bottom left corner. This is because the electrons that react are farther away from the nucleus thus experience less attraction to the nucleus (called nuclear shielding). Therefore their electrons are more easily removed than elements that don't ecperience nuclear shielding.
