Answer:
+3
12 electrons and 15 protons.
Explanation:
The element having 15 electrons and 15 protons have atomic number 15. We know that when an atom lose or gain the electron ions are formed.
Anion formation:
Anion is formed when electron is accept by an atom.
X + e⁻ → X⁻
Cation formation:
Cation is formed when electron lose be an atom.
X → X⁺ + e⁻
The given atom loses 3 electrons thus oxidation number will be +3 and cation is formed.
X → X³⁺ + 3e⁻
Now element X have 15 protons and 12 electrons.
Answer:
3.97 x 10²³atoms
Explanation:
Given parameters:
Mass of ammonia = 11.22g
Unknown:
Chemical amount of ammonia present = ?
Solution:
The chemical amount present in a substance is the number of atoms it contains.
To solve this problem, from the given mass find the number of moles first.
Number of moles = 
Molar mass of NH₃ = 14 + 3(1) = 17g/mol
Number of moles = 
= 0.66mole
1 mole of any substance contains 6.02 x 10²³ atoms
0.66 mole of ammonia will contain 0.66 x 6.02 x 10²³ atoms
= 3.97 x 10²³atoms
Answer:
The information become scientific when it was proved by different experiments and first it become theory then law and we study these information in books
Explanation:
Explanation:
Atomic size gradually decreases from left to right across the periodic table because within a period of elements, all electrons are added to the same shell. However, at the same time, protons are being added to the nucleus, making it more positively charged. The effect of increasing proton number is greater than that of the increasing electron number. Therefore, there is a stronger nuclear attraction. This means that the nucleus attracts the electrons more strongly, pulling the atom's electron shells closer to the nucleus. As a result, the atomic diameter of the atom decreases.
Answer:
identical atom in which an electron moves from the first to the third shell.
Atoms may occupy different energy states. The energy states are discrete, i.e. they occur at specific values only. Therefore an atom can only move to a new energy level if it absorbs or emits an amount of energy that exactly corresponds to the difference between two energy levels.
The lowest possible energy level that the atom can occupy is called the ground state. This is the energy state that would be considered normal for the atom.
An excited state is an energy level of an atom, ion, or molecule in which an electron is at a higher energy level than its ground state.
An electron is normally in its ground state, the lowest energy state available. After absorbing energy, it may jump from the ground state to a higher energy level, called an excited state.
