The heat of formation of Fe2O3(s) is –826.0 kJ/mol. Calculate the heat of the reaction 4Fe(s) + 3O2(g) → 2Fe2 O3(s) when a 53.99-g sample of iron is reacted.

Meat contamination because humans do not eat air or fertilizer so meat contamination is the only logical answer.

Explanation:

ionisation energy decrease down the group as the atomic radius increases. Nuclear charge increases. Number of shell increases so the electron will experience more shielding so it would be easier for the atom to loss electron.

Final answer:

The atomic radius increases as you move down a group from Li to Cs, while the atomic radius generally decreases as you move across a period from Li to Cs. The ionization energy decreases down a group and increases across a period.

Explanation:

The atomic radius is the size of an atom, while ionization energy is the energy required to remove an electron from an atom. In general, as we move down a group from Li to Cs, the atomic radius increases due to the addition of more energy levels. This is because the electrons occupy higher energy orbitals farther away from the nucleus. On the other hand, as we move across a period from Li to Cs, the atomic radius generally decreases. This is because the effective nuclear charge increases, pulling the electrons closer to the nucleus.

Regarding ionization energy, it generally decreases down a group from Li to Cs. This is because the atomic radius increases, therefore making it easier to remove an electron from a larger, higher energy orbital. Conversely, as we move across a period, the ionization energy generally increases. This is because the atomic radius decreases, and the electrons are held more tightly by the increasing nuclear charge.

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Final answer:

The electron configuration that represents the atoms of chlorine in an excited state is 2-7-8. This is because in the excited state, an electron has moved from the second energy level to the third

Explanation:

The electron configuration represents the distribution of electrons in an atom's energy levels. The standard electron configuration for a ground state (normal state) chlorine atom is 2-8-7. However, when an atom is in an excited state, one or more electrons have moved to a higher energy level. In the case of chlorine, an electron from the second energy level could be excited to the third energy level. So, the electron configuration representing an atom of chlorine in an excited state would be option (2) 2-7-8.

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(4) the same quantity of charge and the opposite sign

Further Explanation

Protons, neutrons, and electrons are generally called subatomic particles. They are important components for building atoms. Each atom has a different number of protons, neutrons, and electrons. And ask how the atom maintains its identity and uniqueness. They have different charges and different masses. Also, the role of each subatomic particle is very different from each other. The main difference between Protons, Neutrons, and Electrons can be found in the charge. Protons are positively charged and neutrons are neutral while electrons are negatively charged.

Protons are positively charged. The charge, in this case, is determined by the number of coulombic charges an electron has. The charge of a proton is the same as loading an electron and, approved, can be expressed as 1e. (1e = 1,602 * 10 ^ (- 19) C).

Protons, along with neutrons, are called "nucleons." There are one or more protons in each atom. The number of protons is different in each atom and makes the identity of the atom. When elements are grouped together in a periodic table, the number of protons is used as the atomic number of the element.

Electrons are the third type of subatomic particles, and they are found to orbit around the nucleus in discrete energy levels with discrete. Just like the number of protons, the number of electrons in an atom which carries the identity of each element. The way electrons are published in each element is expressed by their electronic configuration. The number of electrons is similar to the number of protons found in an element. The electron is symbolized as 'e.' Electrons are the only subatomic particles that take part in chemical reactions. They also take part in certain reproductive reactions.

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Details

Grade:  high school

Subject:  chemistry

keywords: proton, electron.

Answer: The correct answer is Option b.

Explanation:

Water is the compound which is formed by the covalent bonding of hydrogen and oxygen atoms. The chemical formula for this compound is

Self-ionization of water is defined as the process in which 2 water molecules react together to produce hydroxide ion and hydronium ion.

The equation for the self ionization of water molecule follows:

By Stoichiometry of the reaction:

2 moles of water molecules react together to produce 1 mole of hydronium ion and 1 mole of hydroxide ion.

Hence, the correct answer is Option b.

Answer:

150

Explanation:

A gas will have the lowest rate of diffusion the lowest temperature from a given set of temperature values.

Since 150 is the lowest value, then this represents the lowest rate of diffusion.

The rate of diffusion is related to the prevalent temperature. When gases diffuse, they move from regions of high concentration to the at of low concentration. They must have enough kinetic energy to move in order to diffuse.

The higher the temperature, the more the kinetic energy and higher rate of diffusion.

Answer:

15º

Explanation:

The rate of diffusion is lower when the temperature is lower. Since 15º is the lowest temperature of the answers, it has the lowest rate of diffusion.