This is a build up of lava which came out of the volcano in previous eruptions, once this lava came out of the volcano it cooled and hardened, over many eruptions layers of hardened volcanic rock will form. The layers are slanted as gravity acts on the lava so it flows down and a little further from the cone.
Answer:
potassium (K) and bromine (Br)
Explanation:
- Periodic table is a table of elements in terms of rows and columns in terms of their chemical and physical properties.
- Elements in the same group or columns have similar physical and chemical properties. For example, elements in the same group have the same number of valence electrons or valency.
- Elements in the same period or rows have similar number of energy levels. For example, potassium and bromine belong to the same period in the periodic table and thus have the same number of energy levels.
Density of unit cell is mathematically expressed as
D =
where, Z = number of atoms/unit cell = 4 (For FCC structure)
Atomic weight of Cu = 63.5 g
a = edge length = 351 pm = 351 X 10^-10 cm
Avagadro's number = 6.023 X 10^23
∴ Density of unit cell =
= 9.752 g/cm3
Now, for FCC structure a = √8 r
where r = radius of Cu
∴ r = a/√8 = (351 X 10^-10)/√8 = 1.24 X 10^-8 cm = 124 pm
Answer:
c. HF can participate in hydrogen bonding.
Explanation:
<u>The boiling points of substances often reflect the strength of the </u><u>intermolecular forces</u><u> operating among the molecules.</u>
If it takes more energy to separate molecules of HF than of the rest of the hydrogen halides because HF molecules are held together by stronger intermolecular forces, then the boiling point of HF will be higher than that of all the hydrogen halides.
A particularly strong type of intermolecular attraction is called the hydrogen bond, <em>which is a special type of dipole-dipole interaction between the hydrogen atom in a polar bond</em>, such as N-H, O-H, or F-H, and an electronegative O, N, or F atom.
Answer:
15 g of solute (HNO₃) are contained in 100 g of solution
Explanation:
There are many kind of concentrations, Molarity, molality, ppm, percent by volume, percent by mass.
Molarity for example are the moles of solute in 1L of solution.
Molality can be defined as the moles of solute in 1kg of solvent.
ppm are the mg of solute in 1kg of solution.
Percent by volume are the volume of solute (mL) in 100 mL of solution.
In this case, percent by mass is the way to say that x grams of solute are contained in 100 g of solution.