Which material is a heat source for the other three materials? Presented is a closed energy system

Which material is a heat source for the other three materials?
Presented is a closed energy system containing equal masses of iron (55 degrees C), basalt (45 degrees C), and water (20 degrees C); air is 30 degrees C.
Which material is a heat source for the other three materials? 1) iron 2) basalt 3) air 4) water - Is the answer iron because it has the most heat?
During the first hour, the total energy in the system will 1) decrease, only 2) increase, only 3) decrease, then increase 4) remain the same - (Shouldn't it remain the same because of the conservation of energy?)
Also during the first hour, the temperature of the water will 1) decrease 2) increase 3) remain the same - (I think it will increase because it acts as a heat sink? Or maybe it will remain the same because water has the highest specific heat?)
Helping me understand one or all of these would be a great help!
You can still ask an expert for help

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

Allison Pena
As far as my knowledge extends,
1st Question: 1. Iron (reason you've given).
2nd Question: 4. Remains same (Law of Conservation of Energy)
3rd Question: 2. Increases, as the system will try to reach a proper equilibrium at a fixed temperature, given by the Principle of Calorimetry.