Avoid placing themselves between moving vehicles and an immovable structure vehicle or stacked materials
Explanation:
Let the age to be found in years is y.
Hence, 
= (\frac{1}{2})^{\frac{y}{5730yr}}
Solve for y as follows.
0.53913 = (\frac{1}{2})^{\frac{y}{5730yr}}
Now, taking log on both the sides as follows
log 0.53913 = 
= 
z = 
= 5107 years
Thus, we can conclude that the time since death is 5107 years.
The wave-mechanical model of the atom is required to explain the spectra of elements with multi electron atoms.
<u>Explanation:</u>
Wave mechanical theory say that every electron surrounding a nucleus occupies a certain orbit and moves in a certain direction, but the orbit is like a wave of energy or cloud but not a ring. It was proposed in the 1920s, when scientists Erwin Schrodinger and Louis Victor de Broglie concluded that the Bohr’s model is not suitable for electron location determination.
Based on many assumptions, scientists began to guess as accurately as possible about the behaviour of electrons at different energy levels around the nucleus. Because all electrons are negatively charged, they tend to push their elbows when they are too close together, moving away and changing direction. Each plane has one or more orbits that have more than one electrons that move around the nucleus in a specific patterns or shape.
Answer:
1.. Lanthanides and actinides are kept separately in the modern periodic table Why?
Lanthanides and actinides are kept separately in the modern periodic table because of following reason:
- If they are placed in the body of the periodic table, the periodic table will become extremely long and hard to recognize
- more scientific and technical reason why they chose to keep the lanthanides and actinides away from the rest of the periodic table was to help in the grouping of elements in blocks
Explanation:
2. Differentiate between long period and short period in any two points.
Long period:
- The 4th and 5th periods of the periodic table are called long periods.
- The long periods coontain 18 elements in them
short period:
- The 2nd and 3rd periods of the periodic table are called short periods.
- The short periods contain 8 elements in them
