Question

name: cristina garcia pd: 5

1. which statements about the development of the periodic table of elements are true?
2. the modern periodic table is arranged by decreasing atomic number.
3. mendeleevs periodic table had empty spaces which were elements that hadnt been discovered yet.
4. the periodic table was never arranged by increasing atomic mass.
5. moseleys periodic table was arranged by increasing atomic number.
6. mendeleev created a periodic table in which he arranged 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

1. examine the periodic table below and determine the correct answer.

i. element b is a halogen
ii. element d is a poor conductor
iii. elements a and c share similar properties
iv. elements e and f have 2 valence electrons
v. elements e and h are inner - transition metals
a) i, ii, iii and iv are true b) i, iii are iv true c) i and v are true d) i, ii and iv are true

1. the bohr models for 5 different neutral elements are given below:

element a element b element c element d element e
which element is correctly labelled below?
element a element b element c element e
alkaline earth metal metalloid has properties similar to rb noble gas
has 12 protons highly reactive has 1 valence electron inert (not reactive)
in period 2 has 10 valence electrons has 11 protons has 1 valence electron
low melting point brittle good conductor poor conductor
a) element a b) element b c) element c d) element e

Explanation:

Question 1:

Mendeleev's periodic table had empty spaces for undiscovered elements and was arranged by increasing atomic mass. Moseley's work led to the modern periodic table arranged by increasing atomic number. So statement 2 is true.

Question 2:

Elements in the same group share similar properties. Halogens are in group 17. Inner - transition metals are in the f - block. Analyzing the positions of elements in the periodic - like structure, statements I and V can be evaluated based on periodic table trends.

Question 3:

For element A with 12 protons (magnesium, an alkaline - earth metal), element B with 13 electrons (aluminum, a metal not a metalloid), element C with 11 electrons (sodium with 1 valence electron and similar to Rb as they are in the same group), element D with 7 valence electrons (not described accurately in all aspects in the options), and element E with 8 valence electrons (a noble gas, inert).

Answer:

1. C
2. C
3. C