Answer:
Explanation:
What is the identity of the atom shown?
Answer:
Chlorine
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given picture it can be seen that there are 17 protons and 18 neutrons are present with in nucleus it means atomic mass is 35 amu and 17 electrons are present out side the nucleus it means its atomic number of 17.
The atomic number of chlorine is 17 and mass number is 35.5 amu thus the given atom is of chlorine.
Elements in the same group/family of the periodic table are similar in what way?
Answer:
D. They have the same number of valence electrons.
Explanation:
The elements in the same group have similar properties due to same number of valance electrons. For example
Consider the group two. It is alkaline earth metals's group. It consist of six members Beryllium, Magnesium, Calcium, Strontium, Barium and radium. All these have two valance electrons.
Electronic configuration of Beryllium:
Be = [He] 2s²
Electronic configuration of Magnesium:
Mg = [ Ne] 3s²
Electronic configuration of Calcium:
Ca = [Ar] 4s²
Electronic configuration of Strontium:
Sr = [Kr] 5s²
Electronic configuration of Barium:
Ba = [ Xe] 6s²
Electronic configuration of radium:
Ra = [Rn] 7s²
