GRADE 9 RUQA( 2nd quarter)

Maria experimented to identify unknown elements based on their flame test colors. She observed a bright yellow flame for Element X and a violet flame for Element Y. Using evidence from her observations, what can she conclude about the identity of these elements?

• Element X is sodium, and Element Y is potassium, based on characteristic flame colors

• Both elements are metals because they produce colored flames

• The flame colors are random and don't indicate specific elements

• More tests are needed before making any conclusions

A student researched three different sources about electron configuration. Source A states that p orbitals hold 6 electrons, Source B states 2 electrons per orbital, and Source C provides conflicting information. Which strategy should the student use to determine the most reliable information?

• Choose the source with the most detailed explanation

• Evaluate the credibility of each source and cross-reference with scientific literature

• Use the information from the newest source only

• Combine all the information from the three sources

Which of the following is false?

• It was Bohr who first defined the main energy levels of the electrons

• It was not Schrodinger who proposed the concept of the spinning electrons

• It was Schrodinger who described the orbitals of the electrons

• It was Bohr who proposed that the atom has a nucleus

The major difference between a 1s orbital and a 2s orbital is that

• The 2s can hold more electrons

• The 1s has a different shape

• The 2s is at a higher energy level

• The 1s can only hold 1 electron

The maximum number of electrons that a single orbital of the 3d sublevel may contain is

• 5

• 2

• 3

• 4

The atomic model in which electrons are seen as moving in a cloud pattern is the

• Thomson’s model

• Quantum Mechanical Model

To understand why atoms form ions, a student should analyze the problem by first identifying what key factor that drives this process.

• The desire to become heavier

• The need to achieve a stable electron configuration (noble gas configuration)

• The requirement to become neutral

• The tendency to increase the atomic number

When evaluating claims about ionic versus covalent bonding, which evidence would be most relevant to support your argument?

• The color of the compounds

• Electronegativity differences, electron transfer vs. sharing, and resulting properties

• The size of the atoms involved

• The phase of matter at room temperature only

How does ionic bonding take place?

• Two non-metallic elements of different kinds form strong intermolecular forces of attraction.

• Two non-metallic elements of the same kind form strong intermolecular forces of attraction.

• A non-metallic element like fluorine is attracted to a non-metallic element like oxygen.

• A metallic element like magnesium transfers an electron to a non-metallic element like chlorine.

When organizing information about covalent compounds for a presentation, which sequence would best help your audience understand the concept?

• Properties first, then definition, then examples

• Examples first, then random facts, then definition

• Definition, electron sharing mechanism, resulting properties, then real-world examples

• Only focus on memorizing the definition.