A hydrogen fuel cell produces energy through an electrochemical reaction between hydrogen and oxygen. Hydrogen gas is fed into the anode side of the fuel cell, where it is split into protons and electrons. The protons travel through an electrolyte membrane to the cathode side, while the electrons flow through an external circuit, creating an electric current. At the cathode, the protons, electrons, and oxygen from the air combine to produce water and release energy in the form of electricity. **

The bonds can be arranged in increasing order of polarity as follows: C-H < N-H < O-H < F-H. This is because fluorine is the most electronegative element, making the F-H bond the most polar, followed by the O-H bond due to the high electronegativity of oxygen. Nitrogen is less electronegative than oxygen, so the N-H bond is less polar than the O-H bond. Lastly, carbon is the least electronegative element in this series, making the C-H bond the least polar. **

A hydrogen fuel cell is a device that converts the chemical energy of hydrogen and oxygen into electricity through an electrochemical reaction. It consists of an anode, a cathode, and an electrolyte membrane. Hydrogen gas is fed into the anode, where it is split into protons and electrons. The protons pass through the electrolyte membrane to the cathode, while the electrons flow through an external circuit, creating an electric current. At the cathode, the protons, electrons, and oxygen from the air combine to produce water and heat as byproducts. This process is clean and efficient, making hydrogen fuel cells a promising alternative to traditional combustion engines. **

To calculate p and q from h and c, we can use the following formulas: p = (h + c) / 2 q = (h - c) / 2 By substituting the values of h and c into these formulas, we can determine the values of p and q. This method allows us to find the two numbers that add up to h and have a difference of c. **

An alkane with 390 carbon atoms will have twice as many hydrogen atoms as carbon atoms. This is because each carbon atom forms four single covalent bonds, and each hydrogen atom forms one single covalent bond. Therefore, the number of hydrogen atoms in an alkane with 390 carbon atoms will be 780. **

An alkane with 390 carbon atoms will have twice as many hydrogen atoms as carbon atoms. This is because each carbon atom forms four single bonds with other atoms, typically hydrogen atoms. Therefore, the alkane with 390 carbon atoms will have 780 hydrogen atoms. **

Stores such as C&A and H&M typically sell mannequins through their own retail channels, such as their physical stores and online platforms. They may also work with third-party vendors or manufacturers to produce and distribute mannequins for sale to other retailers. Additionally, these stores may have partnerships with display and fixture companies to provide mannequins for their stores. Mannequins are often sold as part of a larger range of display and merchandising products for retailers. **

Sure! To solve problem C, you can start by identifying the constraints and requirements given in the problem statement. Then, you can try to come up with a systematic approach to solve the problem, such as using a loop or recursion to iterate through the given input and perform the required operations. For problem H, you can start by understanding the problem statement and identifying the key components involved. Then, you can try to come up with a plan to solve the problem, such as using dynamic programming or a specific algorithm to efficiently compute the desired result. It's important to carefully read and understand the problem statement, and then break down the problem into smaller, manageable steps to find a solution. **