Responder:
27
Explicación:
Dado que:
Número de protones en el átomo X = 29
Carga en el átomo X = +2
Si no hay cargo neto;
número de protones = número de electrones
Sin embargo, dado que el átomo X tiene una carga de +2 (dando 2 electrones).
Por lo tanto,
Número de electrones = número de protones - número de carga en el átomo)
Número de electrones = (29 - 2) = 27
Answer: Bubbles, burning, odor, color change, and rusting.
Explanation: Chemical changes are changes to something that is irreversible.
I think it’s 7.41 because you count up all the atoms and find out how many are x (the large grey ones) and you do 2/27 x 100 which gives you 7.41 :) (sorry if i counted wrong it’s kinda hard)
<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f_{(product)}]-\sum [n\times \Delta H^o_f_{(reactant)}]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28product%29%7D%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28reactant%29%7D%5D)
Hence, the correct answer is Option D.
Answer:
False
Explanation:
While we do know that A. Leeuwenhoek used a simple microscope that consisted of only 1 lens, Hooke used a compound microscope. Although, after trying a compound microscope, Hooke found out that it strained his eyes and continued to use a simple microscope for his <em>Micrographia</em>.
Thus, we can say that the (compound) microscopes used today are different than the (simple) microscope used by Hooke and Leeuwenhoek.
