Answer:
when solid dry ice vaporizes (physical change), carbon dioxide molecules absorb energy. When liquid water becomes ice, energy is released. Remember that all chemical reactions involve a change in the bonds of the reactants.
Explanation:
The correct answer is 2.70 × 10² g or 270 g.
It is given, that the density of a metal is 9.80 g/ml.
Let the mass of a sample of metal be x.
The sample of metal is dropped in 28.9 ml of water, due to which the volume of the water increases to 56.4 ml.
In order to calculate the mass of a metal, there is a need to use the formula, mass = density * volume
Mass = (9.80 g/ml) (56.4 ml - 28.9 ml)
= (9.80 g/ml) (27.5 ml)
= 2.70 × 10² g or 270 g
115 grams total
15/115= 13%
109/115= 87%
.13x 16.4= .277
.87x 86.5= 75.255
75.255+.277= 75.532 deg C
or 75.5 as 3 significant digits
Answer:
Because of the less reactivity of copper.
Explanation:
As well as being resistant to the elements and thereby less likely to be affected by rainfall, hail, and mildew than other types of roofing, copper is also one of the most fireproof materials available. Copper is also highly resistant to thermal changes and thereby doesn't deteriorate quickly.
Magnesium would also corrode PDQ. Magnesium sheeting would also pose an unacceptably high fire hazard.
