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3 years ago

Why do we observe national day

1 answer:

5 0

A national day is a day on which celebrations mark the nationhood of a nation or state. It may be the date of independence, of becoming a republic, or a significant date for a patron saint or a ruler (such as a birthday, accession, or removal). The national day is often a public holiday.

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Why is protein classified as a polymer?

Anika [276]

Its made up of a long chain of monomers so proteins are polymers made of amino acids I hope this helps! ^^;

3 0

3 years ago

Read 2 more answers

2. What ions are present in what ratio in a solution of aqueous calcium chloride?

Alenkasestr [34]

Answer:

$\mathrm{Ca}^{2+} \text { and } \mathrm{Cl} \text { - ions are present in } 1: 2 \text { ratio in a solution of aqueous calcium chloride. }$

Explanation:

Here in Calcium Chloride ionic bond is present in between calcium and chlorine atoms. As we know according to Octet rule calcium have two excess atoms and for matching nearest noble gas electronic configuration. It donate two electrons to gain more stability and form $\mathrm{Ca}^{2+}$ , while chlorine is deficient from one electron to meet nearest noble gas electronic configuration therefore two chlorine atoms accept excess electron from calcium individually and form two $\mathrm{Cl}^{-}$ ions.

$\text { Equation is as follows: } \mathrm{Ca}^{2+}+2 \mathrm{Cl}^{-} \rightarrow \mathrm{CaCl}_{2}$

Hence aqueous solution of calcium chloride breaks the ionic bond pairing in one $\mathrm{Ca}^{2+}$ and two $\mathrm{Cl}^{-}$ ions: $\mathrm{CaCl}_{2} \longrightarrow \mathrm{H}_{2} \mathrm{O} \quad \mathrm{Ca}^{2+}(\mathrm{ag})+2 \mathrm{Cl}(\mathrm{ag})$

5 0

4 years ago

Does a precipitate form when a solution of calcium chloride and a solution of mercury(I) nitrate are mixed together? Write the n

olganol [36]

Answer : Yes, a precipitate form when a solution of calcium chloride and a solution of mercury(I) nitrate are mixed together.

The net ionic equation will be,

$2Hg^{+}(aq)+2Cl^{-}(aq)\rightarrow Hg_2Cl_2(s)$

Explanation :

In the net ionic equations, we are not include the spectator ions in the equations.

Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.

The given balanced ionic equation will be,

$CaCl_2(aq)+2HgNO_3(aq)\rightarrow Ca(NO_3)_2(aq)+Hg_2Cl_2(s)$

The ionic equation in separated aqueous solution will be,

$Ca^{2+}(aq)+2Cl^{-}(aq)+2Hg^{+}(aq)+2NO_3^{-}(aq)\rightarrow Hg_2Cl_2(s)+Ca^{2+}(aq)+2NO_3^{-}(aq)$

In this equation, $Ca^{2+}\text{ and }NO_3^-$ are the spectator ions.

By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.

The net ionic equation will be,

$2Hg^{+}(aq)+2Cl^{-}(aq)\rightarrow Hg_2Cl_2(s)$

7 0

3 years ago

The shielding of electrons gives rise to an effective nuclear charge, Zeff, which explains why boron is larger than oxygen. Esti

Vesna [10]

Zeff = Z - S

Here, Z is the number of protons in the nucleus, that is, atomic number, and S is the number of nonvalence electrons.

For boron, the electronic configuration is 1s₂ 2s₂ 2p₄

Z = 5, S = 2

Zeff = 5-2 = +3

For O, electronic configuration is 1s₂ 2s₂ 2p₄

Z = 8, S = 2

Zeff = 8-2 = +6

Hence, the correct answer is second option, that is, +3 and +6, the Zeff of boron is smaller in comparison to O, thus, boron exhibits a bigger size than O.

3 0

3 years ago

Scientists gather information to understand why and where earthquakes happen. What is the name of the machine that helps them me

creativ13 [48]

There are two scales, one is a Ritcher scale and another one is called a Mercalli scale.

6 0

3 years ago

Why do we observe national day​

Why do we observe national day