Across
- 5. Who is the scientist credited with arranging the elements into a periodic table by increasing atomic mass?
- 6. Which subatomic particle found in the nucleus carries a positive charge?
- 8. Which group in the periodic table consists of non-reactive gases, often called inert gases (Group 18)?
- 11. What is the basic unit of matter that consists of a nucleus and orbiting electrons?
- 12. What is the horizontal row of elements in the periodic table known as?
- 13. What is the dense, positively charged centre of an atom called?
Down
- 1. What is the term for the sum of protons and neutrons in an atom?
- 2. Which group in the periodic table consists of elements known as halogens (Group 17)?
- 3. What do we call atoms of the same element that have different numbers of neutrons?
- 4. Which subatomic particle in the nucleus has no electrical charge?
- 7. Which group in the periodic table contains highly reactive metals, found in Group 1 (excluding hydrogen)?
- 9. What is the vertical column of elements in the periodic table called?
- 10. What is the name of the negatively charged particle that orbits the nucleus?
- 11. What number represents the count of protons in an atom?