Answer: 40 grams
Explanation:
The quantity of Heat Energy (Q) required to heat a substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since Q = 93.4J
M = ?
C = 0.129 J/g.C
Φ = 40.4°C - 22.3°C = 18.1°C
Then, Q = MCΦ
Make Mass, M the subject formula
M = Q/CΦ
M = (93.4J) / (0.129 J/g.C x 18.1°C)
M = 93.4J / 2.33J/g
M = 40 g
Thus, the mass of the lead is 40 grams
Answer:
question 6: winter solstice
question 7: rotation is when an object spins around its axis, revolution is when an object travels in a path around another
question 8: the rotational period is equal to the period of revolution for the moon
question 10: true
Answer: 207.2
Explanation:
In imprecise terms, one AMU is the average of the proton rest mass and the neutron rest mass. This is approximately 1.67377 x 10 -27 kilogram (kg), or 1.67377 x 10 -24 gram (g). The mass of an atom in AMU is roughly equal to the sum of the number of protons and neutrons in the nucleus.
Option 2: 12.0 L of 
at STP.
The standard pressure and temperature values are 1 atm and 273.15 K.
Using the ideal gas equation, number of moles of gas can be calculated which is as follows:
PV=nRT...... (1)
Here, P is pressure, V is volume, n is number of moles, R is gas constant and T is temperature.
Also, in 1 mole of any gas there are 
molecules of the gas. This is known as Avogadro's number and denoted by symbol 
Thus,
Equation (1) can be rewritten as follows:
On rearranging,
Here, all the other terms are constant except volume, thus, gas with volume equal to the volume of 
will have same number of molecules.
Volume of gas and 
gas is same thus, will have same total number of molecules as gas.
