Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
Answer: 
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Putting in the values:
![5.29=-log[H^+]](https://tex.z-dn.net/?f=5.29%3D-log%5BH%5E%2B%5D)
![[H^+]=5.1\times 10^{-6}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D5.1%5Ctimes%2010%5E%7B-6%7D)
Thus ![[H^+]](https://tex.z-dn.net/?f=%5BH%5E%2B%5D)
is
Answer:
:0
Explanation:
One second after the Big Bang, the universe was filled with neutrons, protons, electrons, anti-electrons, photons and neutrinos.Jun 17, 2017
Answer:
If the moles of gas are tripled, the volume must also triple.
Explanation:
According to Avogadro law,
Equal volume of all the gases at same temperature and pressure have equal number of molecules.
The number of moles and volume are directly related to each other. By increasing the number of moles volume also goes to increase with same ratio.
When number of moles decreases the volume also goes to decrease at constant temperature and pressure.
Mathematical expression:
V ∝ n
V = Kn
V/n = k
When volume is changed from V₁ to V₂ by changing the number of moles from n₁ to n₂. Then expression will be,
V₁/n₁ = V₂/n₂
