Answer:
Wetlands are important features in the landscape that provide numerous beneficial services for people and for fish and wildlife. Some of these services, or functions, include protecting and improving water quality, providing fish and wildlife habitats, storing floodwaters and maintaining surface water flow during dry periods. These valuable functions are the result of the unique natural characteristics of wetlands.
The correct answers are as follows:
1. Aluminium will not be useful as food wrapping if it has a much lower melting point.
Aluminum is a metallic element that is malleable and soft, thus, it is easy to beat it into thin sheet, which are used to package food. The thin sheet is called aluminium foil. Aluminum is useful as a food wrapping because it has high temperature and thus, it does not react with food (the hotness of the packaged food is not capable of melting the metal). If the melting point of aluminium is lower, this implies that little temperature, such as the one from hot food will be able to melt aluminum foil, thus allowing the food to be contaminated with the metal.
2. When bleach react with fabric dye chemical change occur in the fabric.
The major element in bleach is chlorine. When laundry bleach is added to a fabric, the chlorine component of the bleach will react with the fabric dye and cause a colour change in the fabric. This type of change is called chemical change, because the original colour of the fabric can not be recovered.
3. Every substance has specific properties, which can be used to identify it. Two of such specific properties are melting point and boiling point. Melting point refers to a specific temperature at which a solid substance will melt while boiling point refers to a specific temperature at which a liquid substance will boil and turn to steam.
Water for instance has a boiling point of 100 degree Celsius. To find out if an unknown substance is water, one can determine the boiling point of such liquid. A boiling point of 100 degree Celsius will strongly signify that the substance is probably water. The same thing applies to melting point. If the specific boiling and melting point of substances are known, then they can be used to identify them.
Answer:
A covalent chemical bond is one in which <u>outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals</u>.
Explanation:
Covalent bonds are formed between two atoms having their electronegativity difference less than 1.7. In this type of bonding the valence electrons of one atoms forms molecular bond with the valence electrons of another atom. The electrons are mutually shared.
Covalent bond can be non-polar as for example formed between hydrogen and carbon atoms.
Also, covalent bond can be polar in nature as that formed between hydrogen and chlorine atoms because the chlorine atom is more electronegative and hence attracts the electrons more towards itself making density of electrons less on hydrogen atom.
Answer:
C
Explanation:
Characteristics used to classify stars include color, temperature, size, composition, and brightness.
Explanation:
The number of orbitals in the sublevels are given below:
Sublevels Orbitals
s 1
p 3
d 5
f 7
a. ls - 1 orbital
b. 5s - 1 orbital
c. 4d - 5 orbitals
d. 4f - 7 orbitals
e. 7s - 1 orbital
f. 3p - 3 orbitals
g. Entire 5th principal energy level : for s, p , f
1 + 3 + 5 + 7 + 9 = 25
h. 6d - 5
