Answer: b} The exact time when an individual atom will decay can be accurately predicted.
c} After each half-life, the amount of radioactive material is reduced by half.
Explanation:
All radioactive decay follows first order kinetics.
Rate law expression for first order kinetics is given by:
where,
k = rate constant
t = time taken for decay process
a = initial amount of the reactant
a - x = amount left after decay process
Expression for calculating half life, which is the time taken by the half of the reactants to decompose is:
Answer: Elements in Group 2
Explanation: The periodic table was arranged by Dmitri Mendeleev specifically around similarites in their chemical behaviors. He found that as atomic number increases, at some point an element starts to react in a manner similar to a previous one. When that happened, he would place the larger element under the smaller one, and eventually noticed a periodicity in the table. Elements in a column (Groups) had similiar chemical properties. We know today that these similarities are due to the electron configuration, and that these configurations repeat themselves. He left gaps in the table when he could find an existing element with properties similar to others in that group. I big leap of faith, but it worked. Elements for those missing boxes were eventually discovered.
The atmospheric pressure will be:
The pressure of the atmosphere resulting from the mercury column is 0.959 atm
What is atmospheric pressure?
The force that an object experiences from the weight of the air above it per unit area are known as atmospheric pressure.
Given: Height of mercury column = 729 mm Hg
To find: The pressure of the atmosphere
Calculation:
The atmospheric column resulting from the mercury column is calculated as follows:
1 atm =760 mm Hg
So, we can convert the 729 mm Hg to atm, and we get
Atmospheric pressure = 729 x 1 atm / 760 = 0.959 atm
Learn more about atmospheric pressure here,
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Answer: 4 N-2 N=2 Nto the left. Change in motion: The box will move to the left. 7.)
Explanation: Please mark branliest.
