Answer: The correct statement is (A new substance is formed and the process can usually NOT be undone.)
Explanation:
A chemical reaction is simply defined as the reaction between two or more elements in which a new substance is formed and the process can usually not be undone. Different types of chemical reaction includes:
-- combination reaction: this occurs when two or more reactants form a product. For example: In the burning of coal, It combines with oxygen to produce carbon dioxide. Also in the burning of wood, carbon dioxide is given off and ashes are formed. Because new substance is being formed, they often can't be undone. The ashes formed can't be changed back into wood. Other types of chemical reaction are listed below.
-- Decomposition reaction
-- Single displacement reaction
-- Double displacement reaction
-- combustion reaction
-- Redox reaction
For the product of a chemical reaction to be undone (reversed), it has to undergo another chemical process different from the one that produced it.
Answer: 317 joules
Explanation:
The quantity of heat energy (Q) gained by aluminium depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
In this case,
Q = ?
Mass of aluminium = 50.32g
C = 0.90J/g°C
Φ = (Final temperature - Initial temperature)
= 16°C - 9°C = 7°C
Then, Q = MCΦ
Q = 50.32g x 0.90J/g°C x 7°C
Q = 317 joules
Thus, 317 joules of heat is gained.
Answer:
A. Fossils of organisms that lived in warm climates have been found in arctic environments.
Explanation:
One of the logic used by Geologists to justify plate movement over a region of space is that the fossils of organisms that lived in warm climates have been found in arctic environments.
- this is as a result of plate tectonics.
- organisms that are well adapted to warm climates in times past have their relics preserved as fossils.
- their fossils are no found today around the arctic environment which are cold
- this suggests that the plate must have drifted or moved
This is the same as its freezing point
hope this helps
