Answer:
After 18 hours, the amount of pure technetium that will be remaining is 12.5 grams
Explanation:
To solve the question, we note that the equation for half life is as follows;
Where:
N(t) = Quantity of the remaining substance = Required quantity
N₀ = Initial radioactive substance quantity = 100 g
t = Time duration = 18 hours
= Half life of the radioactive substance = 6 hours
Therefore, plugging in the values, we have;
Therefore, after 18 hours, the amount of pure technetium that will be remaining = 12.5 grams.
Answer:
1) rusting of metal is both chemical and physical change
2) black ice is an example of a physical change
Explanation:
when metal rusts, it is due to a reaction between the atoms in the metal and the atoms in the air(oxygen) or water(oxygen). When it rusts it also physically changes the look of the metal from silver to dirty brownish maroon.
Black ice is a change in state hence it cannot be a chemical change as the original substance NO LONGER EXISTS in a chemical reaction. It is a physical change however as the ice is changing into a different state of matter.
HOPE THIS HELPS!!!
A. The wings are analogous structures that evolved differently and do not have a similar internal structure.
Answer:
Acid ammonium carbonate // Ammonium bicarbonate.
Explanation:
Hello, a 4 is missing in the fist H, thus:
The presence of the hydrogen between the ammonium and the carbonates characterizes the salt as an acid salt, so you could name it as acid ammonium carbonate or ammonium bicarbonate (similar to the sodium bicarbonate which is .
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