Final Answer:
1. An element is a pure substance made of only one type of atom.
2. The periodic table of elements is a chart that organizes all known chemical elements by their atomic number, electron configuration, and recurring chemical properties.
3. Four kinds of information from the periodic table:
- Element symbol (e.g., H for hydrogen)
- Atomic number (number of protons)
- Element name
- Atomic mass (average mass of atoms)
4. Element number 7 is nitrogen (N); it is a gas at room temperature.
5. Two liquid elements at room temperature:
- Bromine (Br), atomic number 35
- Mercury (Hg), atomic number 80
6. The two elements that are liquid at room temperature are bromine and mercury.
Skill Challenge:
1. The halogen group (Group 17) is made up only of nonmetals.
2. Common properties: they are highly reactive, form salts with metals (e.g., NaCl), and exist as diatomic molecules (e.g., Cl₂).
3. They all have 7 valence electrons.
4. They all tend to gain one electron to form a −1 ion.
Parent Tip: Review the logic above to help your child master the concept of 6th grade periodic table worksheet.
