Question

#1: How did Dmitri Mendeleev deal with elements that had not yet been discovered?

A. He left blanks for them in his periodic table, as he predicted they would be discovered.

B. He gave them names and properties and placed them in the table.

C. He created them in his laboratory and placed them in the table.

D. He ignored them, placing them in the table and shifting others when they were discovered.

**my answer; A

is that right?

Answer 1

A sounds right, it sounds familiar but can't say 100% it's correct

Answer 2

B can't be true because how do you know the properties of unknown substances yet discovered

Answer 3

C is impossible (since elements don't last very long anyways and i don't think mendelev was capable of creating elements)

Answer 4

#2: Which of the following elements have properties similar to those of astatine (At)?

A. F, Br, I

B. Ar, S, P

C. F, Ar, Ne

D. Na, Mg, Al

**my answer; A

is that right?

Answer 5

manmade elements don't last long*

Answer 6

okay :) so #1 is correct :) what about #2?

Answer 7

2A looks good, all 3 are in group 17 along with At

Answer 8

okay :)

and #3?

What is true of the ionic size of the elements in a group as one moves from top to bottom in that group?

A. Ionic size stays the same within the group.

B. Ionic size does not vary in any predictable way within the group.

C. Ionic size decreases from top to bottom within the group.

D. Ionic size increases from top to bottom within the group.

**My answer: D.

is that right?

Answer 9

do u get #3?

Answer 10

yeah i think they increase as you go from top to bottom

http://en.wikipedia.org/wiki/Ionic_radius

Answer 11

kk so #3 is D?

Answer 12

yes

Answer 13

kk thanks :)

Answer 14

kk thanks :)