Answer:
B. Geological Events and Lifeforms
Explanation:
The Earth's Geological time scale is mostly based on Geological Events and Lifeforms.
The Geological time scale provides a division of events on the earth into several time frames.
Each of the time units are based on events through the Earth's history and evolution of life.
The events are often recorded in rock strata and also as fossils which are the preserved remains of organisms.
Answer:
Explanation
Comment
Normally you would just use m*c*delta T. But the c is the same in both cases, so you need just use m*deltaT
Givens
25 degrees
m = ?
T = 25
t = final temp = 75
93 degrees
m = 250
T = 93
t = final temp = 75
Solution
(t - 25)*m = (93 - t) * 250 Remove the brackets
75*m - 25m = 93*250 - 250*75 Combine the right
m(75 - 25) = 23250 - 250*75
50 m = 23250 - 18750 Combine
50 m = 4500 Divide both sides by 50
50*m/50 = 4500/50
m = 90
Answer: 90 grams are needed.
According to Data,
Mass Number = 65
# of Neutrons = 35
As we know,
Mass Number = # of protons + # of Neutrons
Solving for # of protons,
# of protons = Mass Number - # of Neutrons
Putting values,
# of Protons = 65 -35
# of protons = 30
As,
# of protons is the atomic number, so element with atomic number 30 is Zinc.
The cation derived from it has 28 electrons,
So, Zinc having 30 electron will be left with two extra protons, and each proton has +1 charge.
Result:
Zn²⁺
