A. The number of valence electrons increases as atomic mass increases. == Generally true for the representative elements since atomic mass generally increases with increasing Z.
B. The reactivity of alkali metals increases as atomic mass increases. == True. Atomic mass increases down the column and so does reactivity
C. The reactivity of the halogens increases as atomic mass increases. == False. Reactivity decreases down the column.
D. The number of valence electrons decreases across a period. == False. In general, the number of valence electrons increases across a period, particularly for the representative elements.
When we discuss radioactive isotope activity, we consider how many decays or disintegrations occur per unit of time. Therefore, activity is determined by the quantity of disintegrations over time. Ah, the becquerel, or B que, is a measurement unit that is widely used to quantify activity. It is equivalent to one decay or one disintegration per second. Therefore, we occasionally shorten it to one d. per s. The curie, denoted by the letters C I, is a second unit we used to denote activity. The result is 1.4 times 10 to the negative 11. Curie's modify this to Beck, Carell's One Curie from curies. His 10 times 10 times 3.7 's Becca Rell And we are aware that one Decorah is equal to one Decay every second. Therefore, we multiply by 1.4 x 10 - 11 times. There are 5 to 5 decays per second, or 3.7 x 10 to the 10 refined. There is one more conversion because my query now asks us what this would be in decays per minute. We multiply 60 by 5.5 to 5 to get the number of decays per minute from our activity and decays per second. This yields 32 decays per minute, which is significant at 30.
<h3>What are isotopes?</h3>
Isotopes are two or more atom types that have the same atomic number (number of protons in their nuclei), location in the periodic table, and chemical element but have distinct nucleon numbers (mass numbers) as a result of having a different number of neutrons in their nuclei. Although the chemical properties of each isotope of a particular element are almost identical, they differ in their atomic weights and physical characteristics.
To learn more about isotopes:
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The volume of base that is actually needed is 24.5 ml of base.
Titration is a chemical technique which is used in chemistry to find out the concentration of an unknown solution. A solution of known concentration is usually used to determine the concentration of the unknown solution. The known solution is usually added to a specific quantity of the unknown solution until the reaction is complete. An indicator is typically added to the unknown solution and the reaction is deem to be completed when there is a color change in the unknown solution.
Thus, the volume of the base that is required to reach the color end point is actually the base volume that is needed for the reaction.
We need the dissociation constant of benzoic acid which is 6.3x10^'5. Then using the dissociation formula, ka = x2 / (Mo - x) where Mo is the initial concentration. x is determined then. percent ionization is computed as (x/Mo)* 100%. This is then the final answer.
Answer:
6 We know it is closer to 1401.00 than 1400.99 or 1401.01 therefor the 6 sig figs
Explanation:
