Answer:
The natural phenomenon used to describe the length of a meter is the speed of light. The length of a meter is the length a light path travels in 1/(299792458) seconds through a vacuum.
The definition is better due to the uncertainty involved in the use of the length of a standard meter stick because the length of the meter stick could change due to atmospheric conditions from place to place
Explanation:
Answer:
c. can have a large cumulative effect
Explanation:
Noncovalent interactions between molecules are weaker than covalent interactions. Noncovalent interactions between molecules are of various types which include van der Waals forces, hydrogen bonding, and electrostatic interactions or ionic bonding.
van der Waals forces are weak interactions found in all molecules. They include dipole-dipole interactions - formed due to the differences in the electronegativity of atoms - and the London dispersion forces.
Hydrogen Bonds results when electrons are shared between hydrogen and a strongly electronegative atoms like fluorine, nitrogen, oxygen. The hydrogen acquires a partial positive charge while the electronegative atom acquires a partial negative. This results in attraction between hydrogen and neighboring electronegative molecules.
Ionic bonds result due to the attraction between groups with opposite electrical charges, for example in common salt between sodium and chloride ions.
Even though these noncovalent interactions are weak, cumulatively, they exert strong effect. For example, the high boiling point of water and the crystal structure of ice are due to hydrogen bonding.
An ionic compound is made up of a metal and a nonmetal. This eliminates answer choice A, C, and D because both of the elements listed are nonmetal.
Your correct answer is B) One atom of calcium and two atoms of chlorine. This is because calcium is a metal, and chlorine is a nonmetal.
Answer:
C. He shot tiny alpha particles through a piece of gold foil.
Explanation:
In the year 1911, Ernest Rutherford performed the gold foil experiment which gave a deeper perspective to the structure of an atom.
He simply collided a thin gold foil with an alpha particle which he generated from a radioactive source. He discovered that most of the alpha particles passed through the thin gold foil but a few were deflected back. His discovery led to the proposition of the nuclear model of the atom.
Answer: single covalent bond
Explanation: Chlorine is a simple molecule. each chlorine atom can count 8 electrons in its outer shell. with other chlorine atoms. One pair of shared electrons form a single covalent bond.
