Explanation

Molecular crystals are generally soft and stable.

They are composed of molecules held together by relatively weak intermolecular forces, which results in them being easily deformed and having low melting points.

While they are generally stable under normal conditions, they can become unstable under extreme temperatures or pressures.

Explanation

Vacuum distillation is used to distill substances at lower temperatures by reducing the pressure, which lowers the boiling point of the substances.

Explanation

The iodoform test is a chemical reaction used to identify the presence of a methyl ketone group (CH3-CO-) in a compound.

When a methyl ketone reacts with iodine and sodium hydroxide, it produces a yellow precipitate of iodoform.

This makes the iodoform test a reliable way to detect methyl ketones.

Explanation

When an alcohol reacts with an alkyl magnesium halide (Grignard reagent), the product is an alkane.

The Grignard reagent acts as a strong base, removing the acidic hydrogen from the alcohol's hydroxyl group (-OH) and forming a new carbon-hydrogen (C-H) bond, thus creating an alkane.

The other product is a magnesium alkoxide salt. 

Explanation

The aromatization of n-heptane primarily yields toluene.

This process involves the dehydrogenation and cyclization of n-heptane, facilitated by catalysts like Cr2O3/Al2O3 at elevated temperatures, forming a benzene ring with a methyl substituent.

Explanation

The Sabatier-Senderens reaction is a hydrogenation reaction, meaning it adds hydrogen to unsaturated hydrocarbons (alkenes and alkynes) to convert them into saturated hydrocarbons (alkanes). 

Explanation

In 1-butyne, the hydrogen is attached to a carbon with a triple bond (sp hybridization), which makes it more acidic because the carbon can better stabilize the negative charge formed after losing the hydrogen ion.

Explanation

 While an electron always has an electric field due to its charge, its spin generates a magnetic field.

The motion of a charged particle (even if it's just spinning) creates a magnetic field.

Explanation

Emission spectrum is produced when a substance emits light/radiation, showing specific wavelengths.

Explanation

The velocity of a photon is independent of its wavelength. 

The velocity of a photon is determined by the speed of light in a vacuum, which is a constant value (approximately 299,792,458 meters per second) and does not change based on the photon's wavelength or amplitude.

The speed of light is a fundamental constant of nature.