Half-life means that the matter degrades by 50% at each interval. 48.2 days is 2 intervals.
So, it would go down by 50% in the first interval, making it 50g. Then it would go down by another 50% from there, making the final amount of undecayed thorium-234 25g.
Density can be determined as:
d = m /V
whereas, m is mass of compound
v is volume
d = 700 /840 = 0.83 g /mL
Thus density is 0.83 g /mL
Answer:
The molecules absorb heat and acquire more kinetic energy.
Explanation:
In a solid, the solids only vibrate about their mean positions but do not translate. When energy is supplied to the molecule in the form of heat, the molecules vibrate faster. Eventually, they acquire sufficient energy to leave their mean positions and translate. Hence the solid crystal collapses.
When ice is heated, water molecules acquire sufficient kinetic energy to translate. The intermolecular bonds are gradually broken in the solid framework as heat is absorbed. The heat required for this is known as the latent heat of fusion.
The temperature remains constant until phase transition is over, then temperature rise resumes.
This was clear chemical reaction. The Potassium Chlorate reacted with Oxygen in a combustion reaction to change the chemical structure so that it was able to react with Silver Nitrate.
Endothermic, as it makes its surroundings cooler.