C. The valence electrons spend more time around the atom of Cl.
<u>Answer:</u> The element having similar chemical properties that of calcium present in period 3 is magnesium.
<u>Explanation:</u>
In a periodic table, elements are arranged in 18 vertical columns known as groups and 7 horizontal rows known as periods.
Elements arranged in a group show similar chemical properties because of the presence of same number of valence electrons.
We are given:
Calcium is the 20th element of the periodic table having electronic configuration 
It has 2 valence electrons.
The element present in period 3 and have the same number of valence electron or in the same group is magnesium.
Hence, the element having similar chemical properties that of calcium present in period 3 is magnesium.
СН₃ – СН = СН₂ + НCl → CH₃-CHCl-CH₃
<h3>Further explanation</h3>
Alkenes are unsaturated hydrocarbons that have a -C = C- double bond.
If there are 2 double bonds it is called an alkadiene, and if there are three double bonds it is called an alkatriene
General formula for Alkenes: CnH2n
addition reactions to alkenes follow Markovnikov's rule. in the addition reaction of hydrogen halide (HX), the halogen atom (X) will be bonded to the carbon atom that binds less H atom.
If the double-bonded carbon atom has the same number of H atoms attached to it, then the X atom will tend to be attached to the carbon atom with the longer alkyl group.
Addition reaction of propene compounds with HCl
СН₃ – СН = СН₂ + НCl → CH₃-CHCl-CH₃
CH - this carbon atom binds fewer H atoms, so Cl is bonded to this bond
Answer:
Explanation:
Entropy is measure of disorder so as we lower the temperature of gas , its entropy decreases .
Hence at - 200°C entropy of nitrogen will be less than that at - 190°C .
At freezing point ,
entropy of fusion = latent heat / freezing temperature
= .71 kJ / ( 273 - 210 )
= 710 / 63 J mol⁻¹ K⁻¹ .
= 11.27 J mol⁻¹ K⁻¹ .
entropy of fusion = 11.27 J mol⁻¹ K⁻¹ .
