Answer:
Both the initial and final substances are composed of atoms because all matter is composed of atoms. According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and type of atoms after the chemical change as were present before the chemical change.
Explanation:
The atoms that make up your body were produced inside a star and have ... I read once that atoms get recycled so much through the planet that each of ... from William Shakespeare, but I do know this: All of us come from stars. ... If you have gold fillings in your teeth, those atoms came from a star explosion.
Answer: The bond between boron and hydrogen in boron trihydride is covalent bond.
Explanation:
The type of bonding between the atoms forming a compound is determined by using the electronegativity difference between the atoms. According to the pauling's electronegativity rule:
- If
, then the bond is non-polar. - If
, then the bond will be covalent. - If
, then the bond will be ionic.
We are given:
Electronegativity for boron = 2.0
Electronegativity for hydrogen = 2.1
As, 
is less than 1.7 and not equal to 0. Hence, the bond between boron and hydrogen is covalent bond.
Answer: True
Explanation:
The matter exists as solid, liquid or gas. These are called the states of matter. The change of matter from one state to another can be achieved by heating or cooling.
The solid state can be converted into liquid state by providing heat to solid. The heat will make the particles move farther, resulting into liquid state.
Similarly when liquid state is provided heat, it changes to gaseous state. The heat will make the particles move much more faster.
Thus the statement that when heat flows to an object, it can change states is True.
11.0 kg = (11.0 kg)(1000 g/kg) = 11000 g
(11000 g)/(1400 cm3) = 7.857 g/cm3
Simplified = 7.86 g/cm3
Answer is: the approximate freezing point of a 0.10 m NaCl solution is -2x°C.
V<span>an't
Hoff factor (i) for NaCl solution is approximately 2.
</span>Van't Hoff factor (i) for glucose solution is 1.<span>
Change in freezing point from pure solvent to
solution: ΔT = i · Kf · m.
Kf - molal freezing-point depression constant for water is 1,86°C/m.
m - molality, moles of solute per
kilogram of solvent.
</span>Kf and molality for this two solutions are the same, but Van't Hoff factor for sodium chloride is twice bigger, so freezing point is twice bigger.
