Answer:

Explanation:
Hello!
In this case, given the masses of copper, zinc and lead, it is possible to compute the moles via their atomic masses first:

Now, we compute the atomic percentages as shown below:

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Answer:
D
Explanation:
Because it is the only was that you can test using the scientific method.
You should use the joules (J) unit of measurement.
Answer:
Density, 
Explanation:
The attached figure shows a 38.6 kg marble slab. The dimensions of the marble slab is 23 cm × 17 cm × 4 cm
Density = mass/volume
Volume of a cuboid shape is equal to, V = 23 cm × 17 cm × 4 cm
V = 1564 cm³
Density,

or

So, the density of the marble slab is
.
Balance. The fluid in your ears uses pressure to know what orientation your head is in.