they are made by of two types of elementary particles
electrons and quarks
quetion answered by
(jacemorris04)
Answer:
Mg(s) + 2H⁺ → Mg²⁺(aq) + H₂.
Explanation:
- To obtain the overall reaction, we sum the two half-reactions and omit the similar species in the reactants and products sides.
oxidation reaction:
Mg(s) → Mg²⁺(aq) + 2e.
Reduction reaction:
2H⁺ + 2e → H₂.
- So, we add the two half-reactios and obtain the overall reaction:
<em>Mg(s) + 2H⁺ → Mg²⁺(aq) + H₂.</em>
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<span>88 and 84 are mass numbers
the mass number of an element is the sum of the number of protons and the number of neutrons (in which they are each equal to 1 unit (amu))
the number of protons is always the same for a given element (e.g. any C atom has 6 protons), but the number of neutrons varies. Two atoms of the same element (number of protons) with a different number of neutrons are called "isotopes".
So the two strontium atoms differ by 4 neutrons. 84Sr has four neutrons less than 88Sr</span>
Answer:
All of these three are polar molecules or ions
Explanation:
1) CO3 ^2-
It is a polar ion because it consists of one Oxygen atom and three carbon atoms so there is a substantial electroegativity difference between carbon and Oxygen due to which shared electrons are attracted more towards Oxygen creating partial negative charge on it and less towards carbon creating a partial positive charge on it, which makes the overall ion polar.
2) HCN
HCN is a polar molecule because there is substantial electronegativity difference between Carbon and Hydrogen as well as between Carbon and Nitrogen. Due to this negative charge is induced over Nitrogen because electronegativity of Nitrogen is 3.0 and positive charge on Carbon because its electronegativity is 2.5. The overall molecule is polar.
3) NO3^-1
Nitrate ion is also a polar molecule because there are three atoms of Oxygen and one atom of Nitrogen. There is substantial electronegativity difference between oxygen (3.44) and nitrogen (3.0) due to which partial positive charge is created on Nitrogen and partial negative charge created over three Oxygen atoms. The overall molecule is polar.
Hope it helps!
Answer: Reaction (1) , (3) and (4) are accompanied by an increase in entropy.
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
(1) 
3 moles of reactant are changing to 1 mole of product , thus the randomness is increasing. Thus the entropy also increases.
2) 
1 mole of Liquid reactant is changing to 1 mole of solid product , thus the randomness is decreasing. Thus the entropy also decreases.
3) 
1 mole of Liquid reactant is changing to 1 mole of gaseous product , thus the randomness is increasing. Thus the entropy also increases.
4) 
1 mole of Liquid reactant is changing to half mole of gaseous product and 1 mole of liquid product, thus the randomness is increasing. Thus the entropy also increases.
