Answer:lanthanides is the answer and here is a picture for proof
Explanation:
Answer:
atoms move faster
Explanation:
Space is produced when substances are heated. The atoms became extremely energetic and began to move much quicker than usual. When this happens, energy is released in the form of heat, light, and so on. As a result, kinetic energy rises and atoms collide more frequently.
A million years old
Duhhhh
Electrons in an atom can be classified as core electrons and valence electrons. Valence electrons are those electrons which are present in valence shell and participates in bond formation. While, Core electrons are all remaining electrons which are not present in valence shell, hence not take part in bonding.
Atomic number of Selenium (Se) is 34 hence it has 34 electrons with following electronic configuration;
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴
From electronic configuration it is found that the valence shell is 4, and the number of electrons present in valence shell are 6. So,
Core Electrons = Total Electrons - Valence Electrons
Core Electrons = 34 - 6
Core Electrons = 28
Result:
There are 28 core electrons in Selenium.