Chemistry

Periodic Classification and Elements

1,092 Questions

Periodic classification organizes chemical elements based on atomic structure, periodic laws, and elemental properties. It covers historical classification systems, electron configurations, and periodic trends. Test takers preparing for chemistry sections will find these questions crucial for mastering fundamental element properties and atomic interactions.

Periodic table structureAtomic orbitalsElement identificationPeriodic laws

Periodic Classification and Elements Questions

Multiple choice

What is the first element on the Periodic Table?

  1. Oxygen

  2. Mercury

  3. Carbon

  4. Hydrogen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hydrogen is the simplest and lightest element in the universe, consisting of just one proton and one electron. Because its atomic number is 1, it occupies the very first position on the periodic table.

Multiple choice

Hg is the chemical symbol of which element?

  1. Sodium

  2. Oxygen

  3. Helium

  4. Mercury
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The chemical symbol Hg stands for hydrargyrum, which is the Latinized Greek name for liquid silver, commonly known as mercury. Sodium is Na, Oxygen is O, and Helium is He.

Multiple choice

I

  1. iridium

  2. iodine

  3. indium

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

The single-letter chemical symbol I represents iodine, a halogen. Iridium is represented by Ir, indium by In, and silicon by Si.

Multiple choice

Sr

  1. strontium

  2. samarium

  3. tin

  4. selenium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The chemical symbol Sr represents strontium, an alkaline earth metal. Samarium is represented by Sm, tin by Sn, and selenium by Se.

Multiple choice

Rubidium

  1. Ru

  2. Rd

  3. Rb

  4. Rm
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Rubidium is represented by the chemical symbol Rb. Ru is the symbol for ruthenium, while Rd and Rm are not standard chemical symbols.

Multiple choice

Silicon

  1. S

  2. Se

  3. Sn

  4. Si
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Silicon is represented by the chemical symbol Si. S is the symbol for sulfur, Se is for selenium, and Sn is for tin.

Multiple choice

Boron

  1. B

  2. Bo

  3. Bh

  4. Be
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Boron is represented by the chemical symbol B. Be is the symbol for beryllium, and Bh is the symbol for bohrium.

Multiple choice

Helium

  1. He

  2. Hm

  3. H

  4. Hl
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Helium is represented by the chemical symbol He. H is the symbol for hydrogen, and there are no elements with the symbols Hm or Hl.

Multiple choice

H

  1. helium

  2. hydrogen

  3. holmium

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

The chemical symbol H stands for hydrogen, the simplest and most abundant element in the universe. Helium is represented by He, and holmium is represented by Ho.

Multiple choice

Group Two elements lose

  1. one electron

  2. two electrons

  3. one proton

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

Group Two elements, also known as alkaline earth metals, have two valence electrons in their outermost energy level. To achieve a stable octet, they readily lose these two electrons during chemical reactions to form 2+ ions. Protons are located in the nucleus and are not gained or lost during chemical reactions.

Multiple choice

Hydrogen sulphide is a

  1. molecule

  2. atom

  3. mixture

  4. alloy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hydrogen sulfide (H2S) is a chemical compound consisting of two hydrogen atoms covalently bonded to a single sulfur atom, which forms a molecule. It is not a single atom, nor is it a mixture or an alloy because it has a fixed chemical composition.

Multiple choice

What is not a part of an atom?

  1. Protons

  2. Nucleus

  3. Molecule

  4. Electrons
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An atom is composed of subatomic particles including protons, neutrons, and electrons, with protons and neutrons residing in the nucleus. A molecule, on the other hand, is a larger structure made up of two or more atoms bonded together, so it is not a part of a single atom.

Multiple choice

Mobile elements are

  1. N, P, Mo, Mg, K

  2. N, P, Mo, Mg, K, Ca

  3. N, P, Mo, Mg, K, Zn

  4. B, Fe, Ca
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mobile elements in plants include Nitrogen (N), Phosphorus (P), Molybdenum (Mo), Magnesium (Mg), and Potassium (K). These can be redistributed from older to younger tissues.

Multiple choice

Elements most readily mobilized are

  1. P, S, N , K

  2. Ca

  3. Both

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phosphorus, sulfur, nitrogen, and potassium are highly mobile elements in plants, meaning they can be easily redistributed from older to younger tissues.