Answer:
(a)
Correct - In modern periodic table, the atoms are arranged in the order of increasing atomic number.
b) Correct - Elements in a group have similar chemical properties.
(c) Correct - Elements can be classified as metals, metalloids or nonmetals.
Explanation:
(a) Correct - In modern periodic table, the atoms are arranged in the order of increasing atomic number.
Mendeleev's periodic table was the one in which the elements are arranged in the order of increasing atomic mass and thus that have limitations and as a result modern periodic table was introduced in which the elements are arranged in the order of increasing atomic numbers.
(b) Correct - Elements in a group have similar chemical properties.
The modern periodic table consists of 18 groups in which the general electronic configuration is same due to which the elements in the same group usually shows same chemical properties.
(c) Correct - Elements can be classified as metals, metalloids or nonmetals.
Based on the properties the elements can be classified as:
Metals are the good conductors of the heat and the electricity, and are malleable and ductile in nature. Most of them are solids at room temperature and have a characteristic silvery shine.
Nonmetals usually are poor conductors of the heat and the electricity, and are not malleable/ductile and non metals can be gaseous, liquid and solids.
Metalloids are intermediate in the properties of metals and non metals.