1. When Mendeleyev arranged the elements into the periodic table, he found that elements with

fell into groups on the table

A. the same mass
B. similar size
C. Similar properties
D. The same color

2. Every element has its own atomic number. The atomic number is the number of in the nucleus of an atom of the element
A. electrons
B. Neutrons
C. Positrons
D. Protons

3. In the modern periodic table, elements are arranged according to increasing .
A. Atomic number
B. Atomic mass
C. date of discovery
D. Electrical conductivity

My answers
1. B
2. D
3. A

2 answers

I agree with 2 and 3.

1) should similar properties

One column has the noble gases for example. They are all different sizes, but have similar properties.
Thank you so much!!!