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
Use the ideal gas equation PV=nRT. You can compare before and after using P1V1/n1T1=P2V2/n2T2. Since the number of moles remains constant you can disregard moles from the equation and use pressure, volume and temp. Make sure your pressure is converted to atmospheres, your volume is in liters, and your temperature is in kelvins.
Magnesium has atomic no 12
Electronic configuration given by
Or
Answer:One mole of HBr has 6.02 x 1
0
23
molecules of HBr.
1 mole of HBr = 6.02 x 1
0
23
molecules of HBr.-----(a)
X mole of HBr has 1.21 x
10
24
molecules of HBr.
X mole of HBr = 1.21 x
10
24
molecules of HBr------(b)
Taking ratio of (a) and (b)
X / 1 = 1.21 x
10
24
/ 6.02 x 1
0
23
X= 2.009 moles.
Explanation:
