EASE 1 Grade 11 20-21

Which statements about orbitals in a krypton atom are correct?

1.The 1s and 2s orbitals have the same energy as each other but different sizes.

2.The third energy level (n=3) has three subshells and nine orbitals

3.The 3d subshell has five orbitals that have the same energy as each other in an isolated atom.

• 1, 2 and 3

• 1 and 2

• 2 and 3

• 1 only

Answer explanation

1 salah karena different orbitals, different energy level

The table refers to the electron distribution in the second shell of an atom with eight protons.

Which row is correct for this atom

• A

• B

• C

• D

Which of the following electron configurations belongs to a noble gas?

• 1s² 2s² 2p⁵

• 1s² 2s¹

• 1s² 2s² 2p⁶

• 1s² 2s² 2p⁴

What is the electronic configuration of an isolated Ni2 + ion?

• 1s² 2s² 2p⁵ 3s² 3p⁶ 3d⁸ 4s¹

• 1s² 2s² 2p⁵ 3s² 3p⁶ 3d⁸ 4s²

• 1s² 2s² 2p⁵ 3s² 3p⁶ 3d¹⁰ 4s²

• 1s² 2s² 2p⁵ 3s² 3p⁶ 3d⁸

Answer explanation

electron dari 4s akan lebih dulu dikeluarkan sebelum 3d ketika menjadi ion

The first seven ionisation energies of an element between lithium and neon in the Periodic Table are as follows.

What is the outer electronic configuration of the element?

• 2s²

• 2s² 2p¹

• 2s² 2p⁴

• 2s² 2p⁶

The electronic configuration of the two outermost shells of an atom is 3s² 3p⁶ 3d⁵ 4s²

What is this atom?

• manganese

• phosphorus

• strontium

• vanadium

Which ion has the same electronic configuration as Cl⁻?

• F⁻

• P⁺

• Sc³⁺

• Si⁴⁺

The first ionisation energy of chlorine is greater than that of sulfur.

Which factors contribute to this?

1.Chlorine has more protons in its nucleus than sulfur does.

2.Chlorine has greater electron shielding than sulfur does.

3.The covalent bonds in chlorine molecules are stronger than those in sulfur molecules.

• 1, 2 and 3

• 1 and 2

• 2 and 3

• 1 only

Why is the first ionisation energy of aluminium less than that of magnesium?

1.The outer electron in the aluminium atom is more shielded from the nuclear charge.

2.The outer electron in the aluminium atom is in higher energy orbital.

3.The outer electron in the aluminium atom is further from the nucleus.

• 1, 2 and 3

• 1 and 2

• 2 and 3

• 1 only

The first six ionisation energies of four elements are given.

Which element is most likely to be in Group IV of the Periodic Table?

• A

• B

• C

• D