Answer:
The Beer–Lambert law, also known as Beer's law, the Lambert–Beer law, or the Beer–Lambert–Bouguer law relates the attenuation of light to the properties of the material through which the light is travelling.
Explanation:
Please Mark as brainliest
First convert grams to moles:
90.0g *(mole/39.997) = 2.250mole
Remember that molarity is moles per liters:
2.250mol/3L = .750 M
Answer : The correct option is A.
Explanation :
Law of conservation of mass : In the chemical reaction, the mass of reactant must be equal to the mass of product.
A. 
The mass of reactant side = ![2C_4H_{10}+2Cl_2+12O_2=[8(12)+20(1)]+4(35.5)+24(16)=642g](https://tex.z-dn.net/?f=2C_4H_%7B10%7D%2B2Cl_2%2B12O_2%3D%5B8%2812%29%2B20%281%29%5D%2B4%2835.5%29%2B24%2816%29%3D642g)
The mass of product side = 
This means, the mass of product is equal to the mass of reactant. The mass remains conserved and obeys the law of conservation of mass.
The reaction B, C, D, E does not obey the law of conservation of mass.
Therefore, Only reaction A obey the law of conservation of mass.
The scientist that performed the cathode ray experiment leading to the discovery of electrons is J.J. Thomson.
<h3>What is a cathode ray?</h3>
A cathode ray is a tube that contains negatively charged electrode( that is the cathode) which emits electrons when heated at a low pressure.
The cathode ray was used by the scientist, J.J. Thomson to find the ratio of charge to mass (e/m) of the electrons.
Therefore, the scientist that performed the cathode ray experiment leading to the discovery of electrons is J.J. Thomson.
Learn more about electrons here:
brainly.com/question/11316046
#SPJ1