Answer:
4)experiments with cathode ray tubes
Explanation:
when sufficiently high voltage is applied across the electrods, current starts flowing through a stream of particles moving in the tube the negative electrode (cathode) to the positive electrode (anode). These were called Cathode Rays or Cathode Ray Particles
Answer:
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles
MgCl2(s) + H2O(l) → MgO(s) + 2 HCl(g)
Using the standard enthalpies of formation given in the source below:
(−601.24 kJ) + (2 x −92.30 kJ) − (−641.8 kJ) − (−285.8 kJ) = +141.76 kJ
So:
MgCl2(s) + H2O(l) → MgO(s) + 2 HCl(g), ΔH = +141.76 kJ
The correct option is A. Rutherford model of the atom consider an atom to be made up of a central nucleus with electrons orbiting around it. The nucleus is considered to be tiny, heavy and its positively charged while the electrons are negatively charged. The shortcoming of this model is that it was not able to explain how the positive nucleus was not able to attract the negative electrons and pull them inside the nucleus.
