Answer:
After 90 minutes 5.15625 g amount left from total of 165 g.
Explanation:
Given data:
Technetium-104 half life = 18.0 min
Total amount of sample = 165 g
Amount left after 90.0 min = ?
Solution:
First of all we will calculate the number of half lives passes.
Number of half lives = T elapsed / Half life
Number of half lives = 90 min /18.0 min
Number of half lives = 5
Amount left:
At time 0 = 165 g
At first half life = 165 g/ 2= 82.5 g
At 2nd half life = 82.5 g/2 = 41.2 g
At 3rd half life = 41.2 g/ 2 = 20.625 g
At 4th half life = 20.625 g/ 2 = 10.3125 g
At 5th half life = 10.3125 g /2 = 5.15625 g
Thus, after 90 minutes 5.15625 g amount left from total of 165 g.
The depletion of natural resources, the use of chemical and fuel in factories that increased air and water pollution , and increased the use of fossil fuels.
Answer:
Yes.
Explanation:
"These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products."
There is a beginning product, and a reactant is needed in order for something to happen.
For example, according to Newton, something cannot happen until an exterior force comes and stops/pushes it.
Sorry if this is incorrect, I am just 4th grade :(
Answer:
The answer is C
Explanation:
She should make the parachutes smaller in order to decrease the drag forces on the car and bring it to a stop 400 meters after crossing the finish line.
Answer:
O, N, C, H
Explanation:
Electronegativity of an element is the property that combines the ability of its atom to lose or gain electrons. It measures the relative tendency with which the atoms of the element attracts valence electrons in a chemical bond.
On the periodic table, Electronegativity increases across the period but decreases down a group.
To solve the given problem, let us use thE Pauling's table of electronegativities to compare the electronegativities of the elements.
On the table:
C = 2.5
H = 2.1
O = 3.5
N = 3.0
In terms of decreasing electronegativities, the atoms are arranged as:
O N C H
