The periods inside the Periodic Table is B. a horizontal row, and is numbered 1 through 7
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Answer:
The activation energy for an endothermic reaction is quite large and usually takes extra energy from the environment, it is normally not a natural spontaneous process.
Explanation:
- Endothermic reactions require absorbing energy of the surrounding mainly in the form of heat.
- Chemical energy needs energy input to break the bonds.
- Examples of endothermic reactions: Photosynthesis
, melting of ice
, and evaporating liquid water.
Answer:different elements have different number of electrons and shells/orbits thatswhy it have different atomic mass and size.
Explanation:
MgO
MgI2
PbO2
PbI4
These are the possible compounds
Answer:
Approximately , assuming that this gas is an ideal gas.
Explanation:
Look up the standard room temperature and pressure: and .
The question states that the volume of this gas is .
Convert the unit of all three measures to standard units:
.
.
.
Look up the ideal gas constant in the corresponding units: .
Let denote the number of moles of this gas in that . By the ideal gas law, if this gas is an ideal gas, then the following equation would hold:
.
Rearrange this equation and solve for :
.
In other words, there is approximately of this gas in that .