Answer: 3d
Explantion:
1) Period 4 contains the elements with atomic numbers 19 through 36.
2) The elements with atomic numbers 19 (K) and 20 (Ca) fill the orbital 4s.
3) After that, as Aufbau's rule may help you to remember, the energy of the orbitals 3d is lower than the energy of the orbtitals 4p. So, the element 21 (Sc) start fillind the orbital 3d.
There are ten 3d orbitals, so the elements 21 through 30 fill the 3d orbitals.
Those elements, called transition metals are: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn.
When the 3d orbitals are full, the next elements in the same period 4, fill the six 4p orbitals.
excitatory amino acids are the amino acids helps in transformation of neurotransmitters or it helps in transmission of synapsis rapidly in brain of mammal. EAA known to be neurotransmitters for Central nervous system.
Excitatory amino acids count may vary from 50’s to 100’s. They are mostly composed of non-protein- amino acids obtained from algae or fungi.
The possible EAAs are Glutamate (Glu) and Aspartate which act as excitatory neurotransmitters in the brain. They get released from neurons where they induce excitation via metabotropic Glu receptors.
Both glutamate and aspartate having excitatory effect on neurotransmission whereas Gama-amino butyric acid having inhibitory effect on neurotransmission.
Thus, the statement ‘neurotransmitters are chemical brother of gaba’ is indicating the complementary effect of each other.
Answer:
See below
Step-by-step explanation:
Matter is either a <em>pure substance</em> or a <em>mixture.
</em>
Pure substances
- Are composed of one type of atom or molecule.
- Have a constant chemical composition
- Have fixed chemical properties
- Have fixed physical properties
• For example, melting point, boiling point, density, solubility
Mixtures:
- Consist of two or more substances not chemically combined
- Have a variable composition
- Can be separated into two or more components by physical means
• For example, filtration, distillation, centrifugation
- Each component retains its own properties
Electronegativity is a measure of an atom's ability to attract shared electrons to itself. On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group.
The haze is called smog, hope this helps, pls mark brainliest!