Answer:
c) 387g
Explanation:
Water;
Mass = 250g
Specific heat = 4.184
Initial Temp, T1 = 25 + 273 = 298K
Final Temp, T2 = 35 + 273 = 308K
Heat = ?
H = mc(T2 - T1)
H = 250 * 4.184 (308 - 298)
H = 10460 J
Iron;
Initial Temp, T2 = 95 + 273 = 368K (Upon converting to kelvin temperature)
Mass = ?
Final Temp, T1 = 35 + 273 = 308
Heat = 10460 (Heat lost by iron is qual to heat gained by water)
Specific heat = 0.45
H = mc(T2-T1)
M = 10460 / [0.45 (308 - 368)]
M = 10460 / 27
M = 387g
<em>Answer: </em>John Dalton
Explanation: Democritus was a Greek philosopher (470-380 B.C.) who is the father of modern atomic thought. He proposed that matter could NOT be divided into smaller pieces forever. John Dalton created the very first atomic theory.
Answer:- Frequency is
.
Solution:- frequency and wavelength are inversely proportional to each other and the equation used is:

where,
is frequency, c is speed of light and
is the wavelength.
Speed of light is
.
We need to convert the wavelength from nm to m.
(
)

= 
Now, let's plug in the values in the equation to calculate the frequency:

=
or 
since, 
So, the frequency of the green light photon is
.
Answer:vv

Explanation:
The expression for the deBroglie wavelength is:
Where,
is the deBroglie wavelength
h is Plank's constant having value
m is the mass of =
v is the speed.
Wavelength = 5400 Å = 
Applying in the equation as:-

