With the help of a reaction show that zinc is more reactive than iron.

The correct answer is (1) Synthesis

Explanation:

In chemistry, synthesis reaction occurs as two or more substance combine and form a single and complex product, due to this, synthesis reaction is also known as a direct combination, because different to decomposition or replacement reactions the final product includes the substances that were combined. For example, water (H2O) is formed through synthesis by mixing two atoms of hydrogen (H2) and one of Oxygen (H) which means the substances combined form a single substance. Thus, the type of reaction described is Synthesis reaction.

The discoverer of the electron was Thomson. The model of the atom that is missing from the set is the Thomson’s model. J. J. Thomson portrayed his atom model to look like a plum pudding. In his model, he described that an atom is composed mainly of electrons.

Nuclear fusion is the process in which atomic nuclei come together to form heavier nuclei, releasing large amounts of energy in the process. The correct statements are The gas cloud must be very dense, Atoms must be stripped of their electrons, and Temperatures must exceed 14 million Kelvin.

For fusion to occur, certain conditions must be met. The gas cloud or plasma must be dense enough to allow for a sufficient number of collisions between atomic nuclei. Gravitational attraction, on the other hand, is necessary to bring the atomic nuclei close enough together for the strong nuclear force to overcome the electrostatic repulsion between positively charged nuclei.

Atoms must be stripped of their electrons because, in a plasma state, the atoms are ionized, meaning they have lost or gained electrons and exist as charged particles.

Hence, the correct statements are The gas cloud must be very dense, Atoms must be stripped of their electrons, and Temperatures must exceed 14 million Kelvin.

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Answer:

The gas cloud must be very dense.Temperatures must exceed 14 million Kelvin

Molecular clocks use the relationship between the DNA of several groups of organisms to evaluate how long ago they diverged evolutionarily from one another. Therefore, option (4) is correct.

What are Molecular clocks?

The molecular clock can be described as a figurative term for a technique that utilizes the mutation rate of biomolecules to determine the time when two or more life forms diverged. The biomolecular data used are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins.

The benchmarks for calculating the mutation rate are often fossil or archaeological dates. The molecular clock is commonly used in molecular evolution to estimate times of speciation or radiation.

The molecular clock can only give one time period as it cannot assign concrete dates. For viral phylogenetics and ancient DNA studies, the areas of evolutionary biology, the intermediate samples can be utilized to more precisely calibrate the molecular clock.

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