Answer:
C.Plant fossils of the same kind of fernlike plants were found on five continents
Answer:
3 valence electrons
Explanation:
Aluminum has three valence electrons. Valence electrons are found in the outermost shell of an element and are responsible for its valence.
Answer:
A. 0.295 mole
B. 0.055 mole
C.0.144 mole
D. 0.03 mole
Explanation:
To find the amount in moles, we simply use a mathematical relation that connects mass, atomic mass and number of moles.
Number of moles = mass/atomic mass
A. Atomic mass of Argon is 40
n = 11.8/40 = 0.295 mole
B. Atomic mass of zinc is 65
n = 3.55/65 = 0.055 mole
C. Atomic mass of Tantalum is 181
n = 26.1/181 = 0.144 mole
D. Atomic mass of lithium is 7
n = 0.211/7 = 0.03 mole
Answer:

Explanation:
The activation energy represents the energy barrier that reagents must pass to transform into products (or products to transform into reagents in a reverse reaction)
For any reaction, the change in enthalpy is related to the activation energy by the equation

So, the activation energy for the reverse reaction is

**Visible confusion** no problem