Answer:
The change in energy when a neutral atom in the gaseous state adds an electron to form a negative ion.
Explanation:
That is, it is the energy involved in the reaction
X(g) + e⁻ ⟶ X⁻(g)
For most elements, the electron affinity is negative.
However, there are two major exceptions — the values are positive for the elements of Groups 2 and 18 (note the troughs in the graph below).
The Calcium ion is an Alkaline earth metal and wants to give up the 2 s orbital elections and become a +2 cation.
Oxygen has six valence electrons and is looking to gain two electrons to complete the octet (8) electron count in the valence shell making it a -2 anion.
When the charges of the Calcium +2 and the Oxygen -2 are equal and opposite, the ions for an electrical attraction. (Remember Paula Abdul told us "Opposites Attract")
This one to one ratio of charges makes the formula CaO
Answer:
4 g/cm³
Explanation:
Volume(V) = 60 cm³
mass (m) = 240 gm
density (d) = ?
We know density is defined as mass per unit volume so
d = m / v
= 240 / 60
= 4 g/cm³
Hope it will help
We first assume that the gas is an ideal gas so we can use the relation PV= nRT where P is the pressure, V is the volume, n is the number of moles R is the gas constant and T is the temperature. In a closed system, the number of moles should be constant since mass cannot be created or destroyed. So the only thing we can manipulate here is the volume of the system. We do as follows:
PV/T = nR = k
P1V1/T1 = P2V2/T2
V2 = P1V1T2/T1P2
V2 = 1.50 (298.15) V1 / (273.15)(1.0)
V2 = 1.64V1
Therefore, the volume should be changed by a factor of 1.64 of the original volume.
