Answer:
700 calories
Explanation:
Using the formula below:
Q = m × c × ∆T
Where;
Q = amount of heat required (calories)
m = mass of substance (g)
c = specific heat of substance (cal/g°C)
∆T = change in temperature (°C)
According to this question, the following information was provided;
Q = ?
m = 20g
c = 1.0 cal/g °C
∆T = 40°C - 5°C = 35°C
Using the formula; Q = m × c × ∆T
Q = 20 × 1 × 35
Q = 700 calories
Hence, 700 cal of heat energy is needed to raise 20 g of H2O from 5°C to 40°C.
Answer:
Ver explicación
Explanation:
El método científico se refiere al patrón establecido de resolución de un problema científico. Los siguientes son pasos importantes en el método científico;
Haz una observación.
formular preguntas relevantes.
elabore una hipótesis que pueda ser probada.
Diseña un experimento.
Prueba la hipótesis usando tu diseño experimental.
Teniendo en cuenta ambos escenarios, el último caso en el que estudiantes de diferentes capacidades trabajan juntos para resolver un problema refleja mejor el método científico porque pueden hacerse preguntas entre sí y llegar a hipótesis comprobables que pueden demostrarse como verdaderas o falsas mediante experimentos.
The primary reason for this was that Mendeleev
didn't know that atomic numbers actually existed. Atomic numbers
were only discovered a period after Mendeleev's time. The use of X-rays made it
possible to find the atomic number, and those had not been discovered yet. <span>
<span>The periodic table was then arranged in 1913 by Henry Moseley
in an arrangement according to atomic number.</span></span>
A substance that undergoes change during a reaction, usually from coming in contact with another substance
You have to figure out a way to write the two unknown abundances in terms of one variable.
The total abundance is 1 (or 100%). So if you say the abundance for the first one is X then the abundance for the second one has to be 1-X (where X is the decimal of the percentage so say 0.8 for 80%).
203(X) + 205(1-X) = 204.4
Then you just solve for X to get the percentage for TI-203.
And then solve for 1-X to get the percentage for TI-205.
After that the higher percentage would be the most abundant.
203x + 205 - 205x = 204.4
-2x + 205 = 204.4
-2x = -0.6
x = 0.3
1-x = 0.7
Then the TI-205 would have the highest percentage and would be the most abundant.
