From the answers provided, I believe the possible answer would be the last option, silicon, oxygen, and one or more metals. Here's my reasoning: the most abundant mineral group found in the Earth's crust is the silicate group. The silicate materials contain both oxygen and silicon. Silicates are the most common minerals in the rock-formation process, and it has, in fact, been estimated that they make up 75 to 90 percent of the Earth's crust. From this piece of evidence, I can guess that the answer will possibly be D, silicon, oxygen, and one or more metals.
It should also be noted that the additional elements that combine with the silicon-oxygen tetrahedron are involved with the other elements commonly found in the Earth's crust and mantle. They are aluminum, calcium, iron, magnesium, potassium and sodium.
Answer: The property that will best provide evidence that the samples are solid includes:
--> if the substance has a definite shape,
-->if the substance has a definite volume
--> if it's tightly packed.
Explanation:
According to the kinetic theory of matter, every substance consist of very large number of very small particles called molecules. These molecules, which are made up of atoms that are the smallest particles of a substance that can exist in a free state.
Matter can exist in the following states:
--> Solid state
--> liquid state or
--> Gaseous state.
The general property of a substance that is in gaseous state includes:
--> Definite shape: A substance can be grouped as a solid if it's shape is fixed that is, it doesn't depend on the shape of other materials.
--> Definite volume: A substance can be grouped as a solid if it occupies its own shape. This is due to the force of cohesion among its molecules.
--> Tightly packed: A substance can be grouped as solid if the molecular movements of the particles are negligible.
From the samples under observation by Juan and kym, if the sample that possesses the above described qualities, it is a solid rather than liquid or gas.
Answer:
Speed = 3 [km/h]
Explanation:
To solve this problem we must use the definition of speed which relates the distance traveled for a while.
Distance = 1.5 [km] = 1500 [m].
time = 0.5 [hr] = 1800 [s]
Speed = Distance/time
Speed = 1.5/0.5
Speed = 3 [km/h] or 1500/1800 = 0.8333[m/s]
Answer:
A) - 1.8 m/s
Explanation:
As we know that whole system is initially at rest and there is no external force on this system
So total momentum of the system must be conserved
so we will have

now plug in all data into above equation



so correct answer is
A) - 1.8 m/s