Why is this statement false and not true?

Question

The elements calcium, cobalt, copper, cadmium are listed in order from smallest to largest in atomic size. Can anyone explain to me? Thanks!

Answer 1

According to the periodic table, it isn't false.

Answer 2

By "atomic size" are you assuming atomic number?

If you look at the atomic radii of these, they are not in order from smallest to largest. It would be Copper (Cu), Cobalt (Co), Cadmium (Cd), Calcium (Ca)

Answer 3

Check the Periodic Table.

The atomic weight for each is usually listed below the element's symbol.

Ca = 40.08
Co = 58.93
Cu = 63.55
Cd = 112.4

So it isn't false, it's true by weight.

But what about atomic radius? That would be 'size' but in a different way....

In the periodic table, atomic radii increase down a group as new electron shells are added, and decrease left-to-right as the nuclear charge (or number of protons) is increased.

So, as ca, co, cu, and cd are on the Periodic Table, the radius decreases in that order.

Maybe that's it?

Answer 4

If you go here it gives you the sizes of each it is measured by weight.
http://periodic.lanl.gov/default.htm
Name: Calcium
Symbol: Ca
Atomic Number: 20
Atomic Mass: 40.078 amu
Melting Point: 839.0 °C (1112.15 K, 1542.2 °F)
Boiling Point: 1484.0 °C (1757.15 K, 2703.2 °F)
Number of Protons/Electrons: 20
Number of Neutrons: 20
Classification: Alkaline Earth
Crystal Structure: Cubic
Density @ 293 K: 1.55 g/cm3
Color: Silvery

Name: Cobalt
Symbol: Co
Atomic Number: 27
Atomic Mass: 58.9332 amu
Melting Point: 1495.0 °C (1768.15 K, 2723.0 °F)
Boiling Point: 2870.0 °C (3143.15 K, 5198.0 °F)
Number of Protons/Electrons: 27
Number of Neutrons: 32
Classification: Transition Metal
Crystal Structure: Hexagonal
Density @ 293 K: 8.9 g/cm3
Color: silver

Name: Copper
Symbol: Cu
Atomic Number: 29
Atomic Mass: 63.546 amu
Melting Point: 1083.0 °C (1356.15 K, 1981.4 °F)
Boiling Point: 2567.0 °C (2840.15 K, 4652.6 °F)
Number of Protons/Electrons: 29
Number of Neutrons: 35
Classification: Transition Metal
Crystal Structure: Cubic
Density @ 293 K: 8.96 g/cm3
Color: red/orange

Name: Cadmium
Symbol: Cd
Atomic Number: 48
Atomic Mass: 112.411 amu
Melting Point: 320.9 °C (594.05 K, 609.62 °F)
Boiling Point: 765.0 °C (1038.15 K, 1409.0 °F)
Number of Protons/Electrons: 48
Number of Neutrons: 64
Classification: Transition Metal
Crystal Structure: Hexagonal
Density @ 293 K: 8.65 g/cm3
Color: Silvery

Answer 5

Well, when they say smallest to largest, I am assuming that they are talking about atomic radius. The rdius gets bigger as more electrons are present.

Answer 6

False is the same as not true but you still need to do your own homework...sorry.

Answer 7

Try looking in your chemistry book where they have the periodic table. (or find the periodic table online)

Answer 8

I'm sorry I don't have that much time in my hands, but I know this will help you a lot. Please look at the link. ;)
Good luck!!1
~J

Answer 9

look in ur periodic table.