Neutral atoms get smaller as you move across the periodic table from (left to right) because the atom increases in electrons. The more electrons, the bigger the effective nuclear charge (electron and proton attraction) and so basically the atom shrinks.
Always remember that a compound can be separated into simpler substances by chemical methods/reactions. While elements cannot be broken down into simpler substances by chemical reactions. You can do a flame test and spectrum analysis to determine whether a solid material is an element or a compound. Check the boiling and/or melting point, color or density. Also check the solid material’s reaction with oxygen, hydrogen, calcium, or various acids. Examine and study its physical chemistry. The element(s) that may be present may be identified by checking the absorption edges from an x-ray spectrum.
Answer:
We don't have the passage. A random sampling of surfactant uses includes:
- removal of oily materials from objects (clothes and dishes)
- forms remarkable structures called bubbles
- Assists in forming emulsions (e.g., mayonaise and paints)
Explanation:
The structure of a surfactant makes one end of a molecule hydrophilic and the other end hydrophobic. In water, they self-assemble into micelles, an arrangement in which the hydrophobic ends align towards the center, and the hydrophilic ends are pointed outwards to the water. This self-assembly is apparant when bubbles are made. The molecules quickly align themselves such that the hyrophilic ends are oriented inwards towards a thin layer of water and the hydrophobic ends are pointed outward to the air. This arrangement allows a mono-molecular sphere of water molecules to remain stable enough to float, reflect light, and please. These same properties allow the inverse to occur. Soap molecules surround a hydrophobic mass (e.g., the hamburger grease on your shirt) and solubilize it into small micelles which are then carried away in the surrounding water.
Answer:
Option A
Explanation:
A) Yes. The reaction reaches equilibrium when the rate of reaction of the reverse reaction is equal to the rate of the forward reaction , then the only cause for the reverse reaction to be favoured is that the initial rate of the reverse was greater than the forward one.
B) No. The rate constant of the reverse reaction can be greater than the forward one but the rate also depends on concentrations, thus a reverse reaction with greater rate constant can result in the net reaction proceeding in the forward reaction, the reverse reaction or be at equilibrium depending on the concentrations or reactants and products
C) No. A lower activation energy means a higher rate constant , but a higher rate constant does not mean that the net reaction will proceed to the reactants ( see point B)
D) No. The energy changes determine conditions under thermodynamic equilibrium and therefore the net direction of the reaction will depend on the temperature and concentrations of reactants and products with respect to the equilibrium conditions.
