<span>When a substance changes from one state, or phase, of matter to another we say that it has undergone a change of state, or we say that it has undergone a change of phase. For example, ice melts and becomes water; water evaporates and becomes water vapor.These changes of phase always occur with a change of heat. Heat, which is energy, either comes into the material during a change of phase or heat comes out of the material during this change. However, although the heat content of the material changes, the temperature does not.</span>
Answer:
SiH4 is nonpolar and BBr3 is nonpolar and SiF4 is nonpolar.
Explanation:
SiH4 is a non-polar compound. Though the Si–H bonds are polar, as a result of different electronegativities of Si and H. However, as there are 4 electron repulsions around the central Si atom, the polar bonds are arranged symmetrically around the central atom having a tetrahedral shape hence they cancel out making the compound nonpolar.
SiF4 is a nonpolar molecule because the fluorine atoms are arranged symetrically around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out just like in SiH4.
The 3 bromine atoms all lie in the same plane thus the geometry of the compound will be trigonal planar. The BBr3 will be non polar because the three B-Br bonds will cancel out each others' dipole moment given that they are in the same plane.
Answer:
MoClBr₂
Explanation:
First we calculate the mass of bromine in the compound:
- 300.00 g - (82.46224 g + 45.741 g) = 171.79676 g
Then we<u> calculate the number of moles of each element</u>, using their <em>respective molar masses</em>:
- 82.46224 g Mo ÷ 95.95 g/mol = 0.9594 mol Mo
- 45.741 g Cl ÷ 35.45 g/mol = 1.290 mol Cl
- 171.79676 g Br ÷79.9 g/mol = 2.150 mol Br
Now we <u>divide those numbers of moles by the lowest number among them</u>:
- 0.9594 mol Mo / 0.9594 = 1
- 1.290 mol Cl / 0.9594 = 1.34 ≅ 1
- 2.150 mol Br / 0.9594 = 2.24 ≅ 2
Meaning the empirical formula is MoClBr₂.
Answer:
6
8
6
Explanation:
Isotope given:
¹⁴₆C
In specie written as this;
Superscript = Mass number
Subscript = Atomic number
To find the protons, it is the same as the atomic number;
Protons = Atomic number = 6
Neutrons have no charges;
Neutrons = Mass number - Atomic number =
Neutrons = 14 - 6 = 8
The number of electrons is the same as the atomic number = 6
