Modern Periodic Table

Q.

Easy way to learn atomic mass of elements.????

Q.

Define valence shell and valence electrons?

Q. Write the electron-dot structure for sodium, oxygen and magnesium.

Q. Using the formula, $2n^2$ to find the maximum number of electrons in an orbit (shells), identify the elements that have incomplete shells.

1. Helium (Z = 2)
2. Zinc (Z = 30)
3. Argon (Z = 18)
4. Neon (Z = 10)

Q.

Why is it called transition metals?

Q.

Why is Lanthanum in the f-block?

Q.

How many total metalloids are there in the periodic table ?

Q.

The number of protons in the nucleus of an atom is called it’s....................

Q.

The atomic number of an element is 20. In modern periodic table, this element is placed in _______ .

1. 2nd period

2. 3rd period

3. 4th period

4. 1st period

Q.

What do you understand by atomic number and mass number?

Q.

Is iron the most stable element?

Q. Hydrogen is non-metal but why it is place in alkali metals

Q.

In the Modern Periodic Table, the elements are arranged on the basis of their increasing:

1. Atomic number

2. Number of neutrons

3. Mass number

4. Atomic mass

Q.

The identity of a chemical element is determined by which of the following?

1. The number of electrons it possesses

2. The number of neutrons it possesses

3. The sum of the number of protons and neutrons it possesses

4. The number of protons it possesses

Q.

How elements are further classified?

Q. An element X belongs to the 3rd period and 15th group of the modern periodic table.​ What is the atomic number of element X?

1. 7
2. 3
3. 18
4. 15

Q.

how to find valency of elements ?

Q.

Answer in one word:

These elements possess the properties of both metals and non-metals.

Q. was adopted as the basis of modern periodic table.

1. Atomic mass
2. Atomic number
3. Atomic structure
4. Atomic model

Q.

Metals always form negatively charged ions.

1. True
2. False

Q. How to easily remember the periodic table elements

Q.

Which element 's ionic radius smaller than its atomic radius?

1. Sulphur

2. Neon

3. sodium

4. Nitrogen

Q. Question 10
Which of the following is the outermost shell for elements of period 2?

(a) K shell
(b) L shell
(c) M shell
(d) N shell

Q. Why is it said that atoms cannot usually gain or lose 4 electrons? Is it possible under special conditions?

Q.
Why is Carbon 12 isotope used as a standard reference for measuring atomic mass?

Q.

The atomic number of fluorine.

Q. Why did Mendeleev leave some gaps in his Periodic Table?

Q.

What is the abbreviated electron configuration of Platinum (Pt)?

Q.

In the periodic table of the elements, the phrase “middle row anomaly” refers to:

1. Instability of halogen oxides

2. Stability of alkali metal oxides

3. Stability of transition metal oxides

4. Both (A) and (C)

Q. Lithium and sodium have the same number of ___.

1. valence electrons

2. protons
3. electrons
4. shells