Answer:
long range order
Explanation:
A crystal consists of atoms, ions or molecules having both short range and long range order. The atoms, ions or molecules are arranged in a regular pattern throughout the lattice both at immediate vicinities and across the entire crystal structure.
This order accounts for the definite shape and unique properties of crystals which include their sharp melting and boiling points which distinguishes them from amorphous substances.
Answer:
Flourine
Explanation:
Chlorine is a member of the halogen family. Halogens are the elements that make up Group 17 (VIIA) of the periodic table, a chart that shows how elements are related to one another. They include fluorine, bromine, iodine, and astatine.
Answer:
Electron pair geometry- trigonal planar
There is one lone pair around the boron atom
The geometry of BH2 is bent
Explanation:
The valence shell electron pair repulsion theory offers a frame work for determining the shape of molecules based on the number of electron pairs of the valence shell of the central atom in the molecule.
In BH2-, the central atom is boron. There is a lone pair on boron. Owing to the lone pair on boron, the molecular geometry of BH2 is bent.
A or D I think...sorry if it’s wrong
Using the ideal gas law equation, we can find the number of H₂ moles produced.
PV = nRT
Where P - pressure - 0.811 atm x 101 325 Pa/atm = 82 175 Pa
V - volume - 58.0 x 10⁻³ m³
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature - 32 °C + 273 = 305 K
substituting these values in the equation,
82 175 Pa x 58.0 x 10⁻³ m³ = n x 8.314 Jmol⁻¹K⁻¹ x 305 K
n = 1.88 mol
The balanced equation for the reaction is as follows;
CaH₂(s) + 2H₂O(l) --> Ca(OH)₂(aq) + 2H₂(g)
stoichiometry of CaH₂ to H₂ is 1:2
When 1.88 mol of H₂ is formed , number of CaH₂ moles reacted = 1.88/2 mol
therefore number of CaH₂ moles reacted = 0.94 mol
Mass of CaH₂ reacted - 0.94 mol x 42 g/mol = 39.48 g of CaH₂ are needed
