How many valence electrons are in an atom of Se?

• 2
• 8
• 6
• 5

Tags

NGSS.HS-PS1-1

• 2
• 8
• 3
• 13

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The period number tells us...

• How many electron shells an element has

• How many electrons are in the most outer shell

• The mass number

• The valency

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

The number of periods and groups in the

periodic table are______.

• 6,16

• 7,17

• 8,18

• 7,18

The basis of modern periodic law is______.

• atomic number

• atomic mass

• isotopic mass

• number of neutrons

If the distance between two Cl atoms in Cl2

molecule is 1.98Å, then the radius of Cl

atom is ________.

• 0.99 Å

• 0.09 Å

• 0.90 Å

• 0.98 Å

Among the given species A–,A+, and A, the

smallest one in size is ________.

Ionic radius increases across the period from

left to right.

• True

• False

Whic group and period does element X belong to in Periodic Table of Element?

A = 35

Z = 17

• Group 170, Period 30

• Group seventeen, Period 0

• Group 7, Period 3

• Group 17, Period 3

Based on the successive ionisation energies below,how many valence electrons does the element M have?

IE₁ = 943

IE₂ = 1,950

IE₃ = 3,852

IE₄ = 5,492

IE₅ = 23,085

IE₆ = 26,791

IE₇ = 30,024

• 2

• 3

• 4

• 5

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2