Tag: comparison of lanthanoids and actinoids

Quizzes (0) Questions (34)

Questions Related to comparison of lanthanoids and actinoids

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Actinoids belongs to following type of elements:

  1. s -block element

  2. d -block element

  3. f -block element

  4. p -block element
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The two rows that are generally placed underneath the main Periodic Table are called the lanthanide series and the actinide series.

These two rows are produced when electrons are being added to f orbitals.

Therefore, this block of elements are referred to as the "f block".

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Which of the following elements is placed just after actinide series?

  1. Rutherfordium

  2. Unnilpentium

  3. Unnilquadium

  4. Ununbium
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

Actinide series starts with actinium (Z=89) and contains fourteen elements from thorium (Z=90) to lawrencium (Z=103). This is followed by Rutherfordium (Z=104). There Rutherfordium (Z=104) also known as Unnilquadium.

Hence, both a and c are the correct option.

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

The bonds generally formin compounds of Actinoids are:

  1. convalent

  2. ionic

  3. coordinate covalent

  4. metallic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Actinoids are highly electropositive elements, and their compounds are predominantly ionic in nature due to the large size of the ions and the relatively low electronegativity of the metals.

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

In the general electronic configuration,
$(n-2)f^{1-14} (n-1)d^{01} ns^2$ (where n = 7) the configuration will be of:

  1. lanthenides

  2. actinides

  3. transition elements

  4. none
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

General electronic configuration is given:
$(n -2) f^{1 -14} (n -1) d^{0 1} ns^2 ,where ( n =7 )$
$5f^{1 -14} 6d^{0 1 }ns^2$
The seventh period $(n=7)$ is similar to the sixth period with the successive filling up of the 7s, 5f, 6d and 7p orbitals and includes most of the man-made radioactive elements. This period will end at the element with atomic number 118 which would belong to the noble gas family. Filling up of the 5f orbitals after actinium $(Z=89)$ gives the 5f-inner transition series known as the Actinoid Series.

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Most of the radio active elements are present in__________

  1. Lanthanoids

  2. Actinoids

  3. Representative elements

  4. Second transition series
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The actinoids are radioactive elements and the earlier members have relatively long half-lives.

The most common and known element is Uranium, which is used as nuclear fuel when its converted into plutonium, through a nuclear reaction.

Option B is correct.
Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

The actinide contraction is due to:

  1. perfect shielding of $5f$ election
  2. imperfect shielding of $4f$ election
  3. imperfect shielding of $5f$ electron
  4. perfect shielding of $4f$ election
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The actinide contraction is due to imperfect shielding of $5f$ electron. The valence shell electronic configuration of actinoids is $\displaystyle 5f^{1-14}6d^{0-1}7s^2$. With an increase in atomic number, the positive charge on the nucleus increases by $+1$, and one more electron enters in the same $5f$ subshell. There is imperfect shielding of one electron by another electron in the same $5f$ subshell. Due to this, the atomic and ionic radii show a gradual decrease with increase in atomic number.

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Which of the following is true regarding derivation of the name of californium?

  1. The name of californium was derived from the name of the place.

  2. The name of californium was derived from its color.

  3. The name of californium was derived from the name of the scientist who discovered it.

  4. The name of californium was derived from mythological character name.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The name of californium was derived from the name of the state and University of California.