Atomic Structure

What is the number of protons that the element in this image contain?

• 14
• 7
• 15
• 18

The positive particles of an atom are called:

• electrons 
• positrons 
• neutrons 
• protons 

The atomic number of krypton is 36. If the mass number of a krypton atom is 84, which table shows the number of subatomic particles inside and outside the nucleus of the krypton atom?

• 
• 
• 
• 

Atoms of which two elements have a combined total of 23 protons?

• Sodium, Na, and magnesium, Mg

• Boron, B, and carbon, C

• Copper, Cu, and zinc, Zn

• None of these

• Particle W

• Particle X

• Particle Y

• Particle Z

A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material?

• Is the material malleable or ductile?

• Does the material feel hard to the touch?

• Will the material float in water?

• Does the material feel rough or smooth?

• 4 carbon atoms, 11 hydrogen atoms, and 1 oxygen atom

• 7 carbon atoms, 14 hydrogen atoms, and 1 oxygen atom

• 7 carbon atoms, 11 hydrogen atoms, and 8 oxygen atoms

• 6 carbon atoms, 14 hydrogen atoms, and 3 oxygen atoms

Which statement best describes evidence that a chemical reaction occurs as a cake bakes?

• the water in the cake batter evaporates

• the cake rises as gas bubbles form in the baking cake

• the cake takes the shape of the container in which it is baked

• the water in the cake batter is used to keep the cake moist as it bakes

What is found in the nucleus of atoms?

• Protons and electrons.
• Protons, neutrons, and electrons.
• Protons and neutrons.
• Neutrons and electrons.

How many valence electrons does Sodium (Na) have?

• 1
• 2
• 3
• 4