Chapter 2: electron config

What is the correct electron configuration for: Helium

• 1s2

• 1s

• 1

• 1s3

Tags

NGSS.HS-PS1-1

What is the correct electron configuration for: Chromium

• [Ar] 4s1 3d5

• 1s2 2s2 2p6 3s2 3p6

• 1s2 2s2 2p6 3s2 3p6 4s1 3d5

• 1s1 2s2 2p6 3s2 3p6 4s2 3d4

Answer explanation

[Ar] 4s1 3d5 is the shorthand.

remember chromium and copper are unstable, and need one more electron to become stable. so it takes from 4s2.

Tags

NGSS.HS-PS1-1

What is the correct shorthand for: Copper

• [Ar] 4s1 3d10

• [Ne] 4s2 3d9

• [Ar] 4s2 3d9

• [Ne] 3s2 3p6 4s1 3d9

Tags

NGSS.HS-PS1-1

What is the electron configuration of: Sulfur

• 1s2 2s2 2p6 3s2

• 1s2 2s2 2p6 3s2 3p4

• [Ne] 3s2 3p4

• 1s2 2s2 2p6 3s2 3p1

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The mass of Carbon-12 is

Tags

NGSS.HS-PS1-1

How many neutrons are in Carbon-12

What is the Atomic number of Stronium-90

Tags

NGSS.HS-PS1-1

How many electrons are in Oxygen-15

• 8

• 15

• 7

• 16

Tags

NGSS.HS-PS1-1

Which of the following is a metal?

• Lithium

• Hydrogen

• Silicon

• Neon

Which of the following is a non-metal?

• Boron

• Chromium

• Hydrogen

• Strontium