The answer is D.
When one is exposed to large doses of X-Rays, this can cause cell damages or even cancer.
Answer:
they have same number of electrons
Answer:
1.27 × 10⁵ L
Explanation:
Step 1: Given data
- Initial pressure (P₁): 745 Torr
- Initial volume (V₁): 1.41 × 10⁴ L
- Inital temperature (T₁): 21 °C
- Final pressure (P₂): 63.1 Torr
- Final temperature (T₂): -48 °C
Step 2: Convert the temperatures to the Kelvin scale
We will use the following expression.
K = °C + 273.15
K = 21 °C + 273.15 = 294 K
K = -48 °C + 273.15 = 225 K
Step 3: Calculate the final volume of the balloon
We will use the combined gas law.
P₁ × V₁ / T₁ = P₂ × V₂ / T₂
V₂ = P₁ × V₁ × T₂/ T₁ × P₂
V₂ = 745 Torr × 1.41 × 10⁴ L × 225 K/ 294 K × 63.1 Torr
V₂ = 1.27 × 10⁵ L
Answer:
4.8 g H₂O
Explanation:
To find the mass of water, you need to (1) convert grams B₂H₆ to moles B₂H₆ (via molar mass from periodic table), then (2) convert moles B₂H₆ to moles H₂O (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles H₂O to grams H₂O (via molar mass from periodic table).
It is important to arrange the ratios/conversions in a way that allows for the cancellation of units (the desired unit should be in the numerator). The final answer should have 2 sig figs because the given value (3.7 grams) has 2 sig figs.
Molar Mass (B₂H₆): 2(10.811 g/mol) + 6(1.008 g/mol)
Molar Mass (B₂H₆): 27.67 g/mol
1 B₂H₆ + 3 O₂ ---> 2 HBO₂ + 2 H₂O
^ ^
Molar Mass (H₂O): 15.998 g/mol + 2(1.008 g/mol)
Molar Mass (H₂O): 18.014 g/mol
3.7 g B₂H₆ 1 mole 2 moles H₂O 18.014 g
---------------- x --------------- x ----------------------- x ----------------- = 4.8 g H₂O
27.67 g 1 mole B₂H₆ 1 mole
Answer:
B. The temperature of the water when the food sample has finished burning completely.
Explanation:
Heat or thermal energy is a form of energy that transfers from one object to another due to a temperature difference between the objects. The units for heat are joules or calories.
Calorimetry is the measurement of heat energy released or absorbed in a chemical reaction. A calorimeter is used in calorimetry. The calorimeter operates on the Law of Conservation of Energy which states that energy is never created or destroyed but is transformed from one form to another or between objects.
In food calorimetry, the energy released when food is burned is measured by recording the rise in temperature of water in a calorimeter when a given mass of a food sample is burned completely.
Energy can be calculated using the formula: Q = mc ∆T
where Q = the energy in joules or calories, m = the mass in grams, c = specific heat and ∆T = the change in temperature (final temperature - initial temperature).
The temperature of the water when the food sample has finished burning completely is taken as the final temperature of the water. The sample is allowed to smolder for sometime before recording the final water temperature. This is because the water temperature will continue to rise after the flame has gone out.
