Question

Please help me. Chemistry

Answer 1

Answer:

element S is argon and element T is potassium.

4. B

5. D

Explanation:

in an element in periodic table number of elctrons and protons are same.

4. since element S has 18 protons so its atomic number must be 18 so the element is Argon which is the last element of period 4 so the next element will go to period 4 with one extra shell and since the atomic number of next element is 19 the element is Potassium. therefore T is Potassium.

5. number of nucleons in an atom is the number of protons and neutons combined together in an nucleus