All redox reactions involve: (1) the gain of electrons only, (2) the loss of electrons only, (3) both the gain and the loss of electrons, (4) neither the gain nor the loss of electrons.

Which statement correctly describes a redox reaction? (1) Oxidation and reduction occur simultaneously. (2) Oxidation occurs before reduction. (3) Oxidation occurs after reduction. (4) Oxidation occurs, but reduction does not.

What occurs when an atom is oxidized in a chemical reaction? (1) a loss of electrons and a decrease in oxidation number, (2) a loss of electrons and an increase in oxidation number, (3) a gain of electrons and a decrease in oxidation number, (4) a gain of electrons and an increase in oxidation number.

Both low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs) consist of a core of triacylglycerols and cholesterol esters surrounded by a single phospholipid layer. Draw the structural formula of cholesteryl linoleate, one of the cholesterol esters found in this core.

Consider the following equation. $\mathrm{Zn}(\mathrm{s})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{ZnCl}_{2}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{g})$ Which substance is oxidized? (1) Zn(s), (2) HCI(aq), (3) $\mathrm{Cl}^{-}(\mathrm{aq})$, (4) $\mathrm{H}^{+}(\mathrm{aq})$.

Inside the earth and the sun.
(a) Geophysicists have estimated that the temperature at the center of the earth's core is $5000^{\circ} \mathrm{C}$ (or more), while the temperature of the sun's core is about $15$ million $\mathrm{K}$. Express both of these temperatures in Fahrenheit degrees.

How many protons and electrons does the most stable ion for oxygen have?

A. 10 protons, 8 electrons
B. 8 protons, 8 electrons
C. 8 protons, 10 electrons
D. 6 protons, 8 electrons

Determine the charge of each ion.

(a) oxygen ion with $10$ electrons

(b) aluminum ion with $10$ electrons

(c) titanium ion with $18$ electrons

(d) iodine ion with $54$ electrons

Using an iron core inside a solenoid makes the solenoid's magnetic field stronger.

What is understood about electrons in redox reactions?

Marina City in Chicago is a complex of two residential towers that resemble corncobs. Each tower has a concrete cylindrical core with a 35-ft diameter and is 588 ft tall. Find the volume of the core of one of the towers to the nearest whole number.

a. How many 3d electrons are in Fe?
b. How many Sp electrons are in Ba?
c. How many 4d electrons are in I?
d. How many 6s electrons are in Ba?

a. What are valence electrons? b. Where are such electrons located?

A toroidal core has a rectangular cross section defined by the surfaces $\rho=2 \mathrm{cm}, \rho=3 \mathrm{cm}, z=4 \mathrm{cm},$ and $z=4.5 \mathrm{cm}.$ The core material has a relative permeability of 80. The core is wound with two coils $N_{1}=1000$ and $N_{2}=2500$ turns of wire. Find (a) the self-inductances of the two coils; (b) the mutual inductance between coils.