Answer:
T₂ = 19.95°C
Explanation:
From the law of conservation of energy:

where,
mc = mass of copper = 37.2 g
Cc = specific heat of copper = 0.385 J/g.°C
mw = mass of water = 188 g
Cw = specific heat of water = 4.184 J/g.°C
ΔTc = Change in temperature of copper = 99.8°C - T₂
ΔTw = Change in temperature of water = T₂ - 18.5°C
T₂ = Final Temperature at Equilibrium = ?
Therefore,

<u>T₂ = 19.95°C</u>
Answer:
B) Heat is given off.
Explanation:
When heat is given off, a chemical change must have occurred and such a reaction is termed an exothermic reaction.
A chemical change is one in which;
- the process is not easily reversible
- leads to the production of new kinds of matter
- involves change in mass
- requires a considerable amount of energy.
Most chemical reactions are accompanied by heat changes.
For the Colorado river to carve the Grand Canyon It must uplift the Colorado Palteau
Answer:
It has 4 valence electrons
Explanation:
Tin atoms have 50 electrons and 50 protons with 4 valence electrons in the outer shell.
Im pretty sure a cinder-cone volcano