The element with atomic number 17 belongs to which group and period?
A. Group 7, Period 3
B. Group 17, Period 2
C. Group 17, Period 3
D. Group 7, Period 2
Answer: Option C
Solution (By JKExamLibrary)
The element with atomic number 17 is Chlorine. Its electronic configuration is 2, 8, 7. It has 3 shells, so it is in Period 3. It has 7 valence electrons, so it belongs to Group 17 (10 + 7 = 17 in modern IUPAC notation) along with fluorine, bromine, and iodine.
Explanation:
Reacting with metals (e.g., Zn + 2HCl → ZnCl₂ + H₂) to produce hydrogen gas is a chemical property because new substances are formed. Sour taste is physical sensation, color change of litmus is an indicator of chemical reaction but is not itself a chemical property; reactivity is. Conductivity is physical. Chemical properties describe a substance's ability to undergo chemical change.
Consider the following statements about the modern periodic table: 1. Elements are arranged by atomic mass. 2. It has 18 groups and 7 periods. 3. The f-block elements are called inner transition metals. Which are correct?
Explanation:
The modern periodic table is based on atomic number, not atomic mass (Mendeleev's table was based on mass). It consists of 18 vertical groups and 7 horizontal periods. The f-block elements, placed at the bottom, are indeed called inner transition metals (lanthanides and actinides). Thus, statements 2 and 3 are correct.
Explanation:
Diamond has a rigid 3D covalent network, making it the hardest natural material. It does not conduct electricity (no free electrons). It is not layered (graphite is). It is used as an abrasive, not a lubricant.
No comments yet. Be the first to start the discussion!