A.) half - life of a radioactive substance is defined as the time during which concentration of the substance becomes half the initial value.
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
Answer:
Mole ratio for a compound
The chemical formula tells us the mole ratio.
CO2 = 1 CO2 molecule : 1 C atom : 2 O atoms.
Mole ratio for a reaction
The balanced chemical reactions tells us.
C12H22O11 + 12 O2 12 CO2 + 11 H2O
1 C12H22O11 molecule: 12 O2 molecules : 12 CO2
molecules : 11 H2O molecules.
Applications of the mole ratio concept
grams <--> moles <--> moles <--> grams
Explanation:
8. A. Density is independent of size (an intensive property).
9. B. The highest density is 1786 g/20cm^3, or 89.3 g/cm^3. The least is 512 g/20cm^3, or 25.6 g/cm^3. Therefore, the difference is 89.3 - 25.6, or 63.7 g/cm^3.
10. C. A bottle filled with air weighs less than one filled with marshmallows, because air is less dense than marshmallows.
11. D. The number represents the number of protons in the nucleus of the atom, as well as the atomic number of the element.
12. C. The number represents the atomic mass of the element, which is determined based on the relative abundance of each form of the element.
P waves are faster S wave are slower P waves can pass through both solids and liquids S waves bounce of solids
