Reaction on positive electrode (cathode):
PbSO₄₍s₎ + 2H₂O₍l₎ → 2e⁻ + PbO₂₍s₎ + 4H⁺₍aq₎ + SO₄²⁻₍aq₎.
s - solid.
l - liquid.
aq - dissolve in water.
PbSO4 is converted to Pb at one electrode (anode) and to PbO₂ at the other (cathode). Lead battery can be recharged, during recharging, an external source of energy is used.
A mixture is a system that is made up of two or more substances which are not combined chemically. A pure substance is a system that only has one substance. The following are classified as:
1.water : pure substance
<span>2.blood : mixture</span>
<span>3.the oceans : mixture</span>
<span>4.iron : pure substance
5.brass : mixture</span>
<span>6.uranium : pure substance</span>
<span>7.wine : mixture</span>
<span>8.leather : mixture</span>
<span>9.table salt (NaCl) : pure substance</span>
Answer:
Environment A is not undergoing succession, and Environment B is.
Explanation:
Ecological succession is a gradual process in which ecosystems significantly change over time. Ecological succession is a term used by scientists to describe the change in the structure of a community of different species, or ecosystem. This concept of ecological succession stems from a desire to understand the patterns of change in large and complex ecosystems like forests and how they can exist in places known to be recently formed, such as volcanic islands.
In environment A, the ecosystem is not really changing, organisms are merely returning to their natural habitat. It does not represent any change in the ecosystem.
In environment B, the original ecosystem has become grossly modified, first by the appearance of lichen and mosses and subsequently by grasses shrubs and animals. These sequence of events correlate well with the idea of ecological succession presented in the opening paragraph hence environment B is undergoing ecological succession.
Answer:
Moving Across a Period
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons
