Answer:
Explanation:
It makes sense because Helium and Hydrogen only hold 1 and 2 subsequent protons/neutrons and electrons. When the Big Bang happened the entire universe was so hot that it was impossible for elements to form since it was impossible for electrons to stay bound to the atoms. After a few seconds the universe began to cool enough for electrons to bond to atoms and create different elements. Since Helium and Hydrogen have 1 and 2 electrons subsequently we can assume that they were the first elements to be created. Also they are the most abundant elements in the Universe which backs up this theory.
Answer:
CF4
Molecular geometry- tetrahedral
Electron geometry- tetrahedral
NF3
-molecular geometry - trigonal pyramidal
Electron geometry - tetrahedral
OF2
Molecular geometry - bent
Molecular geometry - tetrahedral
H2S
Molecular geometry- bent
Electron geometry - tetrahedral
Explanation:
According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule.
For all the compounds listed, the central atom has four points of electron density. This correspond to a tetrahedra electron pair geometry. The presence of lone pairs on the central atom of OF2,NF3 and H2S accounts for the departure of the observed molecular geometry from the geometry and idealized bond angle predicted on the basis of the VSEPR theory.
Answer:
The presence of hydrogen ions
Explanation:
Nitric acid is formed when hydrogen ions combine with nitrogen oxide ions leading to formation of a strong acid. Wheareas for strong bases the hydroxyl iins must be present, for strong acid, the hydrogen ions contribute to the acidity. Therefore, from the formula of nitric acid, it has hydrogen ions, an indicator of a strong acid.
Bones are made up of a framework of a protein called collagen , with a mineral called calcium phosphate that makes the framework hard and strong. Bones store calcium and release some into the bloodstream when it's needed by other parts of the body.
Answer:
As a hen ages, the eggs that she lays get gradually larger. However, the calcium content deposited in the shell remains the same despite the size of the egg. So the eggshells become thinner as the hen ages.
Explanation:
