Question

1. identify the appropriate block on the periodic table for each description by placing an x in the correct column.

	s block	p block	d block	f block
$kr5s^24d^{10}5p^2$
uranium
calcium
cobalt
selenium
$1s^22s^22p^63s^23p^64s^23d^{10}4p^65s^24d^{10}5p^66s^1$

1. choose the correct element for each statement from the word bank. elements may be used more than once.

word bank: k, ca, sc, br, kr

______ 1. has the largest atomic radius

______ 2. loses 2 electrons to form a +2 ion.

______ 3. has the highest ionization energy

______ 4. has the largest ionic radius

______ 5. known for its limited reactivity

______ 6. is a member of the d - block

1. who arranged the elements according to atomic mass and used the arrangement to predict properties of missing elements?

a. moseley
b. dalton
c. lavoisier
d. mendeleev

Explanation:

Step1: Recall the contributions of each scientist.

• Moseley arranged elements by atomic number.
• Dalton proposed atomic theory.
• Lavoisier is known for work on combustion.
• Mendeleev arranged elements by atomic mass and predicted missing elements.

Step2: Match the description to the scientist.

The question describes arranging by atomic mass and predicting missing elements, which is Mendeleev's work.

Answer:

D. Mendeleev