Answer: A. Limestone rocks dissolving in water
Explanation:
B: This is a physical change; it changes an object physically rather than chemically. It does not change the composition of the concrete, only the shape.
C: This is also a physical change because the water is just dragging sand with it, but not actually changing the composition of it.
D: Similar to option B, this is an example of physical weathering because the ice only divides the rock into different parts but doesn't change the composition or complexity of it.
Metals of Group 1 donate 1 electron from its ns orbital to form ionic bond, where n is the no. of its outermost shell.
Metals of Group 2<span> donate 2 electrons from its ns orbital to form ionic bond, where n is the no. </span>of its <span>outermost shell. </span>
Answer: 3 times as much the potential energy
Explanation:
Potential energy is the energy possessed by an object by virtue of its position.

m= mass of object
g = acceleration due to gravity
h = height of an object
When same object with same is lifted from 10 feet to 30 feet. The height has increased 3 times , thus the potential energy will also get 3 times as much.
Answer:
D.
Explanation:
In Chemistry, electrons can be defined as subatomic particles that are negatively charged and as such has a magnitude of -1.
Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.
Oxygen has a total number of eight (8) electrons and as such the
is able to gain (receive) two (2) more electrons in order to have the same electron arrangements as the noble gas i.e an atom of neon that has a total number of ten (10) electrons.
Hence,
contains the same number of electrons as an atom of neon.
Answer:
the flow of charged particles found in an atom
Explanation: