Question

periodic trends quiz form b pd: 3rd name: cishna gaycta 1. which statements about the development of the periodic table are true? 1. the modern periodic table is arranged by decreasing atomic number. 2. mendeleevs periodic table had empty spaces which elements that hadnt been discovered yet. 3. the periodic table was never arranged by increasing atomic mass. 4. moseleys periodic table was arranged by increasing atomic number. 5. mendeleev created a periodic table in which the elements by order of valence electrons. a) 1,4 and 5 are true b) 2 and 3 are true c) 2 and 4 are true d) 1 and 2 are true

Explanation:

1. The modern periodic table is arranged by increasing atomic number.
2. Mendeleev's periodic table had empty spaces for elements not yet discovered.
3. The original periodic table was arranged by increasing atomic mass.
4. Moseley arranged elements by increasing atomic number and also by order of valence electrons.
5. Mendeleev created a periodic table in which he arranged the elements. All these statements are correct facts about the development of the periodic table.

Answer:

D) 1 and 2 are true