Tetrahedral molecules have a steric number of 4 because they have four bonds and no lone electron pairs. The presence of lone electron pairs affects the shape of the molecule. This repulsion is due to the negative charge of the electrons, which means like charges repel each other.

Tetrahedral Geometry Molecules of methane, CH4, ammonia, NH3, and water, H2O, all have four electron groups around their central atom, so they all have a tetrahedral shape and bond angles of about 109.5°.

For example, a molecule with two electron pairs (and no lone pairs) around the central atom has a linear shape, and one with four electron pairs (and no lone pairs) around the central atom would have a tetrahedral shape.

1. VSEPR Rules:
2. Identify the central atom.
3. Count its valence electrons.
4. Add one electron for each bonding atom.
5. Add or subtract electrons for charge (see Top Tip)
6. Divide the total of these by 2 to find the total.
7. number of electron pairs.
8. Use this number to predict the shape.

The VSEPR theory describes five main shapes of simple molecules: linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.

The acronym “VSEPR” is pronounced “vesper” for ease of pronunciation.

Molecules have size and shape. Atoms bond together to form molecules that have different sizes and shapes. All water molecules have the same shape because the bonds between the hydrogen atoms and the oxygen atom are more or less the same angle. Single molecules can be made up of thousands and thousands of atoms.

This, believe it or not, is a microscope. It can help us see very small particles like molecules by feeling the particle with the tip of its needle. These very powerful microscopes are called atomic force microscopes, because they can see things by feeling the forces between atoms. …

Anything infinitely small does not exist although some objects act as if they are point-like. In mathematical Real numbers – no. The set of Real numbers , , is defined to have the Archimedean property .

The Sun

The largest known structure in the Universe is called the ‘Hercules-Corona Borealis Great Wall’, discovered in November 2013. This object is a galactic filament, a vast group of galaxies bound together by gravity, about 10 billion light-years away.

These explosions generate beams of high-energy radiation, called gamma-ray bursts (GRBs), which are considered by astronomers to be the most powerful thing in the universe. What’s more, these GRBs could be killing our chances of ever discovering life on other planets.

Heaviest Object on Earth Weighs 116B Pounds

• Great Wall of China; 116 billion pounds.
• Three Gorges Dam (China); 20.8 billion pounds.
• Great Pyramid of Khufu (Egypt); 12 billion pounds.
• Gullfaks C installation oil storage facility (North Sea); 3 billion pounds.
• SSCV Thialf crane vessel (various); 2.1 billion pounds.

Mercury

liquid hydrogen

A gallon is a measurement of volume and density is directly proportional to the mass of a fixed volume. A gallon of milk is heavier than a gallon of water.

Answer to the weight question posted above: Water is the heaviest at 8.3 pounds per gallon. The other liquids weigh: diesel (7.1 pounds per gallon), and propane (4.0 pounds per gallon).

PHILADELPHIA (CBS) — New research shows milk is better than water for hydration. That’s according to scientists from Saint Andrew’s University in Scotland. They found the sugar, fat and protein in milk keeps people hydrated longer.