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The molar mass of methane (CH4) is calculated by adding the atomic masses of carbon (approximately 12 g/mol) and hydrogen (approximately 1 g/mol). Therefore, the molar mass of CH4 is 12 g/mol + 4 x 1 g/mol = 16 g/mol. The mass percentage of carbon in CH4 is given by (mass of carbon / total mass) x 100% = (12 g / 16 g) x 100% = 75%.

Tend to gain electrons in chemical reactions. Non-metals typically have a high electronegativity and tend to gain electrons to achieve a stable electron configuration. This results in the formation of negatively charged ions (anions) during chemical reactions.

An alpha particle is represented by the Greek letter '\alpha'. Alpha particles are a type of ionizing radiation ejected by certain types of radioactive materials. They consist of two protons and two neutrons, so they can be represented as a Helium-4 nucleus.

When a substance is oxidized, it loses electrons. Oxidation is a chemical reaction that involves the moving of electrons. Specifically, it's a process that involves the substance losing electrons. This is an old definition of oxidation, based on the oxygen's role in reactions. The modern definition of oxidation involves an increase in oxidation state by a molecule, atom, or ion.

If a blue litmus paper turns red when dipped into a solution, it indicates the presence of an acid in the solution. Acids turn blue litmus paper red.

NaCl, commonly known as sodium chloride or table salt, is an example of an electrovalent bond. Sodium (Na) donates one electron to chlorine (Cl), resulting in the formation of Na+ and Cl- ions, which are held together by the ionic bond.

According to Graham's law of diffusion, the ratio of the diffusion rates of two gases is the inverse of the square root of the ratio of their molar masses. Therefore: Rate of A / Rate of B = \sqrt(Molar mass of B / Molar mass of A) Rate of A / Rate of B = \sqrt(64 g/mol / 32 g/mol) = \sqrt2 = 1.41 So, the ratio of their diffusion rates is approximately 2:1.

The contact process is used for the industrial production of sulfuric acid (H2SO4), not any of the options provided. The process involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3) which is then absorbed in sulfuric acid to form oleum (H2S2O7). The oleum is then diluted with water to form sulfuric acid.

One unique property of water is that it expands when it freezes. Most substances contract and become denser when they freeze, but water expands and becomes less dense. This is why ice floats on water.

When sodium reacts with water, it undergoes a highly exothermic reaction, producing sodium hydroxide (NaOH) and hydrogen gas (H2).

Chlorine gas exists in the gaseous state at room temperature (around 25 degrees Celsius) and standard pressure.

In a molecule with three bonding pairs and no lone pairs around the central atom, the electron pairs arrange themselves in a trigonal planar geometry, with bond angles of approximately 120 degrees.

Isotopes of an element have the same number of protons (which defines the element) but may have different numbers of neutrons. Since atoms are electrically neutral, the number of protons must equal the number of electrons in an atom.

In the electrochemical series, also known as the reactivity series, Sodium is placed at the top. The electrochemical series is a list of elements in the order of their standard electrode potentials (or redox potentials). Elements at the top of the series are more reactive and have a greater tendency to lose electrons and form positive ions.

Copper is known for its multiple oxidation states, including +1 and +2, and its compounds are used in pigments and paints to create various colors, such as blues and greens.