Methane (CH4) forms the molecular solid.
<u>Explanation:</u>
- The molecules which are held together by intermolecular forces are called molecular solids. It is maintained by solids rather than bonds. The force which holds these solids are weaker than other solids.
- It consists of discrete molecules and the cohesive force which binds them together is Vanderwall's force, dipole-dipole interaction and hydrogen bonding. They are held together by an ionic bond or covalent bond.
- The weak intermolecular forces have relatively low melting points which are less than 300 degrees Celsius.
- Organic solvents dissolves Molecular solvents. Many of the molecular solids are soft electrical insulators with low density.
Certain naturally occurring radioactive isotopes are unstable: Their nucleus breaks apart, undergoing nuclear decay. ... All elements with 84 or more protons are unstable; they eventually undergo decay. Other isotopes with fewer protons in their nucleus are also radioactive.
<h3>
Answer:</h3>
4.73 × 10^4 m
<h3>
Explanation:</h3>
From the question;
Frequency of the photon = 634 × 10^12 Hz
We are required to calculate the wavelength of the photon.
We need to know the relationship between wavelength and frequency of a wave.
The relationship between f and λ is given by;
c = fλ
Where c, is the speed of light, 2.998 × 10^8 m/s
Therefore, to get the wavelength we rearrange the formula such that;
λ = c ÷ f
= 2.998 × 10^8 m/s ÷ 634 × 10^12 Hz
= 4.73 × 10^-5 m
But we require wavelength in nm
1 M = 10^9 nm
Therefore;
Wavelength = 4.73 × 10^-5 m × 10^9 nm/m
= 4.73 × 10^4 m
Hence, the photon's wavelength is 4.73 × 10^4 m
Answer:
Because of the less reactivity of copper.
Explanation:
As well as being resistant to the elements and thereby less likely to be affected by rainfall, hail, and mildew than other types of roofing, copper is also one of the most fireproof materials available. Copper is also highly resistant to thermal changes and thereby doesn't deteriorate quickly.
Magnesium would also corrode PDQ. Magnesium sheeting would also pose an unacceptably high fire hazard.
A) true
b) false The atomic mass is never less than the atomic number.
c) this one is a bit tricky. For hydrogen, the atomic mass can equal the atomic number IF you are rounding the mass to the nearest whole number. That only works for hydrogen, though
d) false The larger the element, the more neutrons that are needed to keep the nucleus stable.
e) true
f) true
