Answer:
1.00 × 10¹⁸
Explanation:
1. Calculate the <em>energy of one photon</em>
The formula for the energy of a photon is
<em>E</em> = <em>hc</em>/λ
<em>h</em> = 6.626 × 10⁻³⁴ J·s; <em>c</em> = 2.998 × 10⁸ m·s⁻¹
λ = 477 nm = 477 × 10⁻⁹ m Insert the values
<em>E</em> = (6.626 × 10⁻³⁴ × 2.998× 10⁸)/(477 × 10⁻⁹)
<em>E</em> = 4.165× 10⁻¹⁹ J
2. Calculate the <em>number of photons</em>
Divide the total energy by the energy of one photon.
No. of photons = 0.418 × 1/4.165 × 10⁻¹⁹
No. of photons = 1.00 × 10¹⁸
Answer:
4) Each cytochrome has an iron‑containing heme group that accepts electrons and then donates the electrons to a more electronegative substance.
Explanation:
The cytochromes are <u>proteins that contain heme prosthetic groups</u>. Cytochromes <u>undergo oxidation and reduction through loss or gain of a single electron by the iron atom in the heme of the cytochrome</u>:

The reduced form of ubiquinone (QH₂), an extraordinarily mobile transporter, transfers electrons to cytochrome reductase, a complex that contains cytochromes <em>b</em> and <em>c₁</em>, and a Fe-S center. This second complex reduces cytochrome <em>c</em>, a water-soluble membrane peripheral protein. Cytochrome <em>c</em>, like ubiquinone (Q), is a mobile electron transporter, which is transferred to cytochrome oxidase. This third complex contains the cytochromes <em>a</em>, <em>a₃</em> and two copper ions. Heme iron and a copper ion of this oxidase transfer electrons to O₂, as the last acceptor, to form water.
Each transporter "downstream" is <u>more electronegative</u><u> than its neighbor </u>"upstream"; oxygen is located in the inferior part of the chain. Thus, the <u>electrons fall in an energetic gradient</u> in the electron chain transport to a more stable localization in the <u>electronegative oxygen atom</u>.
Answer is: chemical.
Making a pancake from batter is chemical change (chemical reaction), because new substances are formed, the atoms are rearranged and the reaction is followed by an energy change.
Batter is thin dough that is poured into a pan to make pancakes.
In physical change, the same substance is present before and after the psysical change, just with different form or state of matter.