Answer:
Physical Property
Explanation:
Density, mass, volume, color, melting and boiling points, etc. are all physical properties. No matter what changes, the chemical makeup stays the same.
Flamability, acidity, toxicity, etc. are chemical properties, because they chemically change the makeup of the object/thing.
Answer: 20.7 kJ
Explanation:
According to first law of thermodynamics:
=Change in internal energy
q = heat absorbed or released
w = work done or by the system
w = work done on the system=
{Work is done on the system is positive as the final volume is lesser than initial volume}
w = 4.51 kcal = 
(1kcal = 4.184kJ)
q = +1.79 kJ {Heat absorbed by the system is positive}
Thus for a system that receives 1.79 kJ of heat from surroundings and has 4.51 kcal of work done on it at the same time is 20.7 kJ
Answer:
Heating a substance increases the speed at which molecules move.
Explanation:
Answer:
Neodymium makes flints inside of lighters. It also takes away the green color off of glass. Rhenium is added with tungsten and molybdenum which makes filaments for lamps. Sulfur makes sulfuric acid which makes batteries and cleaners and can process ores.
Explanation:
An interesting fact for each element:
Neodymium is known for the atomic symbol Nd and the atomic number 60.
Rhenium is known for the atomic symbol Re and the atomic number 75.
Sulfur is known for the atomic symbol S and the atomic number 16.
I hope the Answer answers your question. I gave you some facts to remember those elements in the periodic table!
Missing question: Express the salt concentration in kg/m³.
Answer is: the salt concentration is 9.8 kg/m³.
m(NaCl) = 9.8 g ÷ 1000 g/kg.
m(NaCl) = 0.0098 kg.
V(solution) = 1 L = 1 dm³.
V(solution) = 1 dm³ ÷ 1000 dm³/m³.
V(solution) = 0.001 m³.
d(solution) = m(NaCl) ÷ V(solution).
d(solution) = 0.0098 kg ÷ 0.001 m³.
d(solution) = 9.8 kg/m³.
