Exploring Flame Tests and Spectroscopy 2

What is observed during a flame test when an electron falls from an excited state to the ground state?

• The electron emits sound.

• The electron emits light.

• The electron changes color.

• The electron disappears.

Which of the following cations would you expect to produce a green flame in a flame test?

• Sodium

• Lithium

• Copper

• Potassium

Why is it important to dip the cotton swab in water before using it in a flame test?

• To prevent the cotton swab from burning.

• To make the flame test more colorful.

• To clean the cotton swab.

• To make the salt stick to the swab.

What is the purpose of performing a control test with a wet cotton swab in a flame test?

• To see the natural color of the flame.

• To ensure the burner is working.

• To test the purity of the water.

• To compare the flame color with the salt samples.

If a flame test produces a lavender color, which metal ion is likely present?

• Sodium

• Potassium

• Copper

• Lithium

Explain why different metal ions produce different colors in a flame test.

• Because they have different numbers of protons.

• Because they have different energy levels for electrons.

• Because they have different atomic masses.

• Because they have different melting points.

How can a spectroscope be used to identify an unknown element in a flame test?

• By measuring the temperature of the flame.

• By comparing the pattern of spectral lines to known elements.

• By observing the brightness of the flame.

• By counting the number of electrons in the element.

What might cause a flame test to produce inaccurate results when identifying a mixture of metal ions?

• The flame is too hot.

• The colors of the ions cancel each other out.

• The cotton swab is too wet.

• The burner is not clean.