Answer: 45
Explanation:
Recall that mass number = number of protons + number of neutrons. Hence, the mass number of the atom
= 22 + 23
= 45
Furthermore, the atomic number is equal to the number of protons. Hence, since the number of protons is 22. the atom has an atomic number of 22
Thus, An atom that contains 22 protons,
23 neutrons, and 22 electrons would have a mass of approximately 45
Answer:
Al(NO3)3(s)--------> Al^3+(aq) + 3NO3^-(aq)
Explanation:
The equation shown above describes the dissolution of Al(NO3)3 in water using the lowest coefficients.
This occurs when solid Al(NO3)3 is added to water. It dissolves to give rise to ions as shown. This is a property of all ionic substances.
Answer: The correct answer is it emits light.
Explanation:
When an electron is present in ground level that is the lower energy level and moves to the higher energy level, the energy is provided to the electron which means that it absorbs light. This is known as absorption.
When an electron present in the higher energy level comes back to the lower energy level, it emits radiations in the form of light. This is known as emission.
Hence, the correct answer is it emits light.
Answer:
The correct option is B
Explanation:
One of the claims of John Dalton's atomic theory is that atom is the smallest unit of matter (which suggests that there are no particles smaller than an atom in any matter). This claim has been disproved by the modern atomic theory which established that there are particles smaller than atom (called subatomic particles). These particles are electrons, protons and neutrons.
One of the modern atomic theory was by Neils Bohr, who proposed that <u>electrons move in circular orbits around the central nucleus</u>. Thus, the electrons of iron can also be said to be present in a region of space (circular path) around the nucleus. This proves that option B is the correct option as John Dalton's theory did not even recognize the electron(s) nor the nucleus.
