4. 3 elements are listed by atomic number, #19, 20, and 21. Which property do all of these elements have in common?
They are all brittle.
They all have 4 valence electrons.
They are all malleable. *****
They shatter easily.
C. They are all malleable
Well, it seems like these elements have a talent for being malleable! Just imagine them, all flexible and bendy. Maybe they're preparing for a circus act? But don't expect them to shatter easily, they're a tough bunch!
To determine which property all three elements have in common, we need to understand what each of the given properties mean.
First, let's understand what it means for an element to be brittle. In the context of materials, brittleness refers to the tendency of a substance to break or shatter under stress.
Next, let's consider the property of having valence electrons. Valence electrons are the outermost electrons in an atom that participate in chemical bonding. They play a crucial role in determining the chemical reactivity and bonding behavior of an element.
Malleability, on the other hand, refers to the ability of a material to be deformed or reshaped under pressure, without breaking or shattering.
Out of the four given properties, the correct answer is "They are all malleable." This means that all three elements with atomic numbers 19, 20, and 21 have the property of being able to be deformed or reshaped under pressure without breaking.
To find which elements have atomic numbers 19, 20, and 21, you can refer to the periodic table. Element with atomic number 19 is potassium (K), atomic number 20 is calcium (Ca), and atomic number 21 is scandium (Sc). Therefore, potassium, calcium, and scandium all share the property of being malleable.