Answer:
oxygen
Explanation:
The given isotope has 8 protons and 8 electrons, so the atomic number of the given isotope is 8, which is the atomic number of oxygen.
Answer: option C. Sulphur
Explanation:
Answer:
Q = -14322.77 J
Explanation:
Given data:
Mass of water = 55.0 g
Initial temperature = 87.3°C
Final temperature = 25.0 °C
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.0 °C - 87.3°C
ΔT = - 62.3 °C
Q = 55.0 g×4.18 J/g.°C × - 62.3 °C
Q = -14322.77 J
Answer:
compound
Explanation:
We already know that the original substance was pure. If this substance was pure and it was powdery in nature then we have a footing to start from.
Secondly, a 4.93 g of shinny metallic liquid was left behind. This shinny metallic liquid must be an element.
Since there was a loss in mass during heating, it follows that there were other components of the pure powder.
If the reasoning stated above is correct, then the substance is a compound.
Answer: Two electron configurations of elements that would have similar chemical properties are (2) and (4).
Explanation:
(1) 
(2) 
(3) ![[Ar]4s^23d^5](https://tex.z-dn.net/?f=%5BAr%5D4s%5E23d%5E5)
(4) ![[Ar]4s^23d^{10}^4p^5](https://tex.z-dn.net/?f=%5BAr%5D4s%5E23d%5E%7B10%7D%5E4p%5E5)
Valence electrons : These are the electrons present in last principal quantum number of an atom of the element.
Two electron configurations represent elements that would have similar chemical properties are (2) and (4). This is because number of valence electrons present in both of them are same that is seven valence electrons . Also valence electrons of both the elements are present in p-orbital which means that they both belongs to same group in a periodic table. The members of same group in a periodic table have similar chemical properties.
