D) during chemical reactions the number and types of atoms
Answer:
The speed of a spound wave in this water is 1484.1 m/s
Explanation:
Step 1: Data given
Frequency = 349.2 Hz
Wavelength = 4.25 m
Step 2: Calculate the speed
v = f*λ
⇒ with v= the speed of a sound wave in this water
⇒ with f = the frequency = 349.2 Hz
⇒ with λ = the wavelength = 4.25 m
v = 349.2 Hz * 4.25 m = 1484.1 m/s
The speed of a spound wave in this water is 1484.1 m/s
Answer:
2000 years
Explanation:
A radioactive molecule will continuously decay and turn into another molecule. This nature of the radioactive molecule makes them can be used to estimate the age of an object. Half-life is the unit of time needed for radioactive molecules to decay to half of its mass. The formula for the mass remaining will be:

Where
N(t)= number of the molecule remains
N0= number of molecule initially
t= time elapsed
t1/2= half time
We have all variable besides the half time, the calculation will be:




3= 6000/ (t1/2)
t1/2= 6000/3= 2000
The half-life is 2000 years
Answer:
Steps of a scientific investigation include:
1. Identifying a research question or problem
2. Forming a hypothesis
3. Gathering evidence
4. Analyzing evidence
5. Deciding whether the evidence supports the hypothesis
6. Drawing conclusions
7. Communicating the results.
Answer:
2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.
Explanation:
The balanced reaction is:
4 Fe + 3 O₂ → 2 Fe₂O₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
- Fe: 4 moles
- O₂: 3 moles
- Fe₂O3: 2 moles
The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
You can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe reacts with 3 moles of O₂, how much moles of Fe will be needed if 4.7 moles of O₂ react?

moles of O₂= 6.27
But 6.27 moles of Fe are not available, 5.4 moles are available. Since you have less moles than you need to react with 4.7 moles of O₂, iron Fe will be the limiting reagent.
So you can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, how many moles of Fe₂O₃ will be produced if 5.4 moles of Fe react?

moles of Fe₂O₃= 2.7 moles
Then:
<u><em>2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.</em></u>