From the curve on the graph we can see, when y=50 x=4.5
the unit of x-axis is in "billions of years", so the answer is 4.5 billions of years
Answer: The most likely identity of the substance is iron.
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed=
Joules
m= mass of substance = 11.9 g
c = specific heat capacity = ?
Initial temperature of the water =
= 25.0°C
Final temperature of the water =
= 45.0°CChange in temperature ,
Putting in the values, we get:


The specific heat of 0.45 is for iron and thus the substance is iron.
Three times larger I think.