I would say letter D.
A is biology.
Ecology has to do with distribution of animals.
The letter in parentheses after a chemical formula indicates c) the physical state of the substance.
The letters can be:
→ (s) for solid.
→ (l) for liquid.
→ (g) for gazeous.
→ (aq) for an aqueous solution (like NaCl (aq) - NaCl is dissolved in water)
Lead reacts very slowly with dilute hydrochloric acid to give lead chloride<span> and </span>hydrogen<span> gas. </span>
<span>lead + hydrochloric acid —> lead chloride + hydrogen
Pb(s) + 2HCl(aq) —> PbCl2(aq) + H2(g)</span>
<span>Lead reacts very slowly with dilute sulphuric acid to give </span>lead sulphate<span> and </span>hydrogen<span> gas. </span>
<span>lead + sulphuric acid —> lead sulphate + hydrogen
Pb(s) + H2SO4 (aq) —> PbSO4(aq) + H2(g)</span>
<span>Lead reacts very slowly with dilute nitric acid to give </span>lead nitrate<span> and </span>hydrogen<span> gas. </span>
<span>lead + nitric acid —> lead nitrate + hydrogen
Fe(s) + 2HNO3(aq) —> Fe(NO3)2(aq) + H2(g)</span><span> </span>
Answer:
P
Explanation:
Information about various chemical compounds and elements. ... P. 2.19. S. 2.58. Cl. 3.16. Ar. n.a.. 4. K. 0.82. Ca. 1.00. Sc. 1.36. Ti. 1.54. V. 1.63. Cr. 1.66. Mn. 1.55. Fe. 1.83. Co. 1.88. Ni. 1.91. Cu. 1.90. Zn. 1.65. Ga. 1.81 ... electronegativity scale, although in the Allred-Rochow scale, helium has the highest electronegativity.
