Answer: As matter cycles and energy flows through living systems and between living systems and the physical environment, matter and energy are conserved in each change. The carbon cycle provides an example of matter cycling and energy flow in ecosystems.
Explanation:
Answer: Breaking covalent bonds in molecules results in the dissipating the energy of atoms held together in molecules.
Explanation: By way of introduction,
Covalent bonds are one of four types of chemical bonds. The other three are ionic bonds, metallic bonds and hydrogen bonds. Each bond type differs in the way atom share electrons. In covalent bonds, two atoms completely share one or more pairs of electrons. These bonds are quite strong.
Covalent bonds form between atoms when the total energy present in the newly formed molecule is lower than the energy present in each of the atoms alone. The lower energy when bonded results from the fact that atoms are more stable when their outer electron shells are full. Atoms can fill their outer shells by sharing electrons with other atoms though the formation of covalent bonds.
It is important to know that there is a symmetrical relationship between the amount of energy released during the formation of a covalent bond, the amount of energy needed to break the bond. Breaking covalent bonds requires energy, and covalent bond formation releases energy.
This energy is measured as heat using the units joules or calories or kilocalories.
The amount of energy released during molecule formation can be estimated by counting the number and types of bond in a molecule. For instances, a methane molecule has one carbon atom bound to four hydrogen atoms via four single carbon-hydrogen covalent bonds. Carbon-hydrogen bonds release 100 kcal/mole of energy when formed, so the total energy needed to break all the bonds in a methane molecule is 100 kcal x 4 or 400 kcal.
Active transport uses up energy while passive transport does not.
I believe that the common features of the three is that they usually give a suggestion that brain stimulation is effective when treating severe forms of depression. These methods are usually used after other methods have been tried and failed. They involve the stimulation of the brain.