before the lava rises to the earth's surface it's called magma. Although lava and magma are often used interchangeably, technically magma is the name for the hot molten rock (mixed with gases and mineral crystals) that collects in chambers beneath the Earth's crust.
Explanation:
Iron has TWO valence electrons......
The forces between particles are called intermolecular forces. A strong intermolecular force means that the particles are tightly paced and is associated with the solid phase. Moderate intermolecular force is associated with the liquid state and little to no intermolecular force is associated with the gaseous state. Temperature has a direct effect on the state of matter in which the substance exists has. Generally speaking, a rise in tempreature changes a substance from the solid to liquid phase and from liquid to gaseus phase. The reverse is true, if the temperature lowers then the substance will go from gas to liquid and liquid to solid. It is important to not that temperature affects intermolecular forces. As the temperature increases then the individual particles become excited and gain enough energy to over the intermolecular forces and so the particles seperate from each other.
<u>Answer:</u> The mass of sample A after given time is 99.05 g.
<u>Explanation:</u>
All the radioactive reactions follows first order kinetics.
The equation used to calculate half life for first order kinetics:
We are given:
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = 84.2 s
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = 250 g
[A] = amount left after decay process = ?
Putting values in above equation, we get:
![0.011s^{-1}=\frac{2.303}{84.2s}\log\frac{250}{[A]}](https://tex.z-dn.net/?f=0.011s%5E%7B-1%7D%3D%5Cfrac%7B2.303%7D%7B84.2s%7D%5Clog%5Cfrac%7B250%7D%7B%5BA%5D%7D)
![[A]=99.05g](https://tex.z-dn.net/?f=%5BA%5D%3D99.05g)
Hence, the mass of sample A after given time is 99.05 g.
In order to answer this question, the dimensions of the brick in centimetres need to the converted to dimensions in metres. In order to convert centimetres to metres you need to divide by 100. Doing this yields brick dimensions of 0.15 m x 0.06 m x 0.12 m. Multiplying the length, width and height together yields the volume of 0.00108 cubic metres.
