Answer:
Molarity= 1.69M
Explanation:
m= 14.8, Mm= 35, V= 0.25dm3, C= ?
Moles = m/M= C×V
Substitute and Simplify
m/M= C×V
14.8/35= C×0.25
C= 1.69M
A. The radioactive decay equation is N = N0
where T is the
half-life (5730 years), N0 is the number of atoms at time t = 0 and
N is the number at time t.
Rewriting this as:
(N/N0) = 
Since N = (1/8) N0 and
substituting known values:
1/8 = 
Taking ln of both
sides:
ln(1/8)= -ln(2)*t/5730
t = - 5730 * ln(1/8) /
ln (2)
t = 17,190 years
The tree was cut down 17,190
years ago.
B. N0 = 1,500,000 carbon-14 atoms
Since N = (1/8) N0
N = 187,500 carbon
atoms left
If you take your mom's advice, a. the room will be cooled by minimizing heat transfer by reflection.
The Sun is heating your room by its <em>radiation</em>.
The aluminium foil is shiny, so it reflects the Sun’s radiation back outside the window.
<em>Convection</em> is the transfer of heat caused by the air moving around in your room.
<em>Conduction</em> occurs only when a hot object is in contact with a cooler object.