Answer:
A = 2
B = 1
Explanation:
The atomic number of lithium is 3.
Its atomic mass is 7 amu.
It is present in group group 1.
It has one valance electron.
Lithium is alkali metal it form salts.
It is silvery soft metal. It has lowest density as compared to all other metals.
It react vigorously with water.
It is used in rechargeable batteries which are used in camera, mobile, laptops etc.
The electronic configuration of Li:
Li₃ = 1s² 2s¹
Thus,
A = 2
B = 1
Answer:
Heat required to melt 26.0 g of ice at its melting point is 8.66 kJ.
Explanation:
Number of moles of water in 26 g of water: 26×
moles
=1.44 moles
The enthalpy change for melting ice is called the entlaphy of fusion. Its value is 6.02 kj/mol.
we have relation as:
q = n × ΔH
where:
q = heat
n = moles
Δ
H = enthalpy
So calculating we get,
q= 1.44*6.02 kJ
q= 8.66 kJ
We require 8.66 kJ of energy to melt 26g of ice.
Answer:
V1= 0.305L
Explanation:
To find the initial volume of 1.25M potassium fluoride needed to make tge dilution specified in the question, we can use: C1 × V1 = C2 × V2
Since the question wants the volume in litres, convert 455 mL to L
455/ 1000
= 0.455 L
Now make the substitution
1.25 × V1 = 0.838 × 0.455
Rearrange to make V1 the subject
V1=

Im not positive but i think it is When it is a gas?