- Task 1:
- a: Section C
- b: Metals
- Task 2a:
- conductor of heat and electricity: Metal
- insulator of heat and electricity: Non-metal
- shiny: Metal
- low density: Both
- dull: Non-metal
- sonorous: Metal
- brittle: Non-metal
- malleable: Metal
- ductile: Metal
- high density: Metal
- not sonorous: Non-metal
- Task 2b:
- The unknown element is a metal. Sonority, electrical conductivity, and ductility are characteristic properties of metals.
- CHALLENGE:
- The unknown substance is a non-metal. Non-metal oxides typically dissolve in water to form acidic solutions, which turn universal indicator orange. If the substance were a metal, its oxide would likely form a basic solution, turning the indicator blue or purple.
- Task 2 (Patterns):
- 1:
- The rows of the Periodic Table are called periods.
- The columns of the Periodic Table are called groups.
- 2a:
- Across the period from sodium to silicon, the melting point increases.
- 2b:
- Across the period from lithium to carbon, the melting point also increases. The trend is similar in both periods, showing a general increase in melting point across a period.
- Task 3 (Mendeleev):
- 1a:
- He, Ne, Ar, Kr, Xe
- 1b:
- All symbols consist of one or two letters, with the first letter capitalized and the second (if present) lowercase. They are derived from the element’s name.
- 1c:
- Radon’s symbol, Rn, does not follow the pattern because it is derived from “radon” rather than from its historical name or origin like radium (Ra), which is related to radioactivity. The naming convention for noble gases often reflects their discovery context or properties, and radon was named for its radioactive nature, leading to a different symbol structure.
- Task 3 (Mendeleev 2):
- a:
- The numbers represent atomic masses.
- b:
- Elements in each column have similar chemical properties and the same number of valence electrons.
- c:
- Mendeleev predicted 44 because it fits the pattern of increasing atomic mass between calcium (40) and titanium (48). He left a gap for an undiscovered element and estimated its atomic mass based on the average or logical progression of values in that group.
Parent Tip: Review the logic above to help your child master the concept of physical science periodic table worksheet.
