How can I solve this question.

Bryan is doing a science experiment on the stomata of plants. Bryan has a tomato plant. He uses wax to cover all the stomata on

skad [1K]

Answer: The answer is B

4 0

2 years ago

A student mixed a small amount of iron filings and sulphur powder in a dish. He could not

Temka [501]

Answer:

$\huge \boxed{\mathrm{Carbon \ disulphide}}$

Explanation:

Carbon disulphide is the liquid that can be used to separate iron fillings and sulphur powder.

When carbon disulphide is poured into the dish, the sulphur powder gets easily dissolved in the carbon disulfide. The iron fillings are left to settle on the bottom of the dish.

The iron fillings can get seperated through filtration. When the mixture of sulphur powder and carbon disulphide gets completely evaporated, the sulphur powder is left over.

7 0

3 years ago

Which of the following equations does not demonstrate the law of conservation of mass?

enot [183]

The third option does not obey the law of conservation of mass.

Option 3.

Explanation:

The law of conservation of mass states that the sum of the masses of reactants should be equal to the sum of the masses of the products.

For example, if we consider the first option to verify if it obeys law of conservation of mass or not, 2 Na + Cl₂ → 2 NaCl

So one way to verify it is to find the mass of Na, then multiply it with 2, and then add this with 2 times of mass of chlorine. So this sum should be equal to the 2 times mass of NaCl. But it is somewhat lengthy.

Another way to easily determine this is to check if the elements are present equally in both sides. Such as, in reactant side and product side 2 atoms of Na is present . Similarly, the Cl atoms are also present in equal number in both reactant and product side. Thus this obeyed the law of conservation of mass.

Like this, if we see the second option, there also 1 atom of Na is present in reactant and product side and 2 molecules of H is present in reactant and product side, 1 oxygen is present in reactant and product side and 1 Cl is present in reactant and product side. So it also obeys the law of conservation of mass.

But in the third option, P₄ + 5 O₂→ 2 P₄O₁₀, here, there is 4 atoms of P in reactant side but in product side there is (4*2) = 8 atoms of P. Similarly, the number of atoms of oxygen in reactants and product side is also not same. So the third option does not obey the law of conservation of mass.

The fourth option also obeys the law of conservation of mass as the number of atoms of each element is same in both the product and reactant side.

Thus, the third option does not obey the law of conservation of mass.

5 0

3 years ago

A rectangular block has the following dimensions: 3.21 dm, 5.83 cm, and 1.84 in. The block has a mass of 1.94 kg. What is the de

spin [16.1K]

The density of the rectangular block in g/mL is 7.0.

Given the following data:

Mass of block = 22.8 gra1.94 kg

Length of block = 3.21 cm

Width of block = 5.83 cm

Height of block = 1.84 in.

To find the density of the block in g/mL:

First of all, we would determine the volume of the rectangular block by using the following formula:

$Volume = length$ × $width$ × $height$

Conversion:

1 in = 2.54 cm

5.83 in = X cm

Cross-multiplying, we have:

$X = 2.54(5.83)\\\\X = 14.81 \; cm$

$Volume = 3.21$ × $5.83$ × $14.81$

Volume = 277.16 cubic centimeters.

Note: Milliliter (mL) is the same as cubic centimeters.

1000 grams = 1 kg

Y grams = 1.94 kg

Cross-multiplying, we have:

Y = 1940 grams

Now, we can find the density:

$Density = \frac{Mass}{Volume}\\\\Density = \frac{1940}{277.16}$

Density = 7.0 g/mL

Therefore, the density of the rectangular block in g/mL is 7.0.

4 0

3 years ago

What is the difference between a mixture and compound

bonufazy [111]

A compound is made up of a single type of molecule. A mixture, on the other hand, is made up of different substances that can be distinguished from one another.
As an example:
Water (pure water) is a compound since it's only made up of water molecules
Seawater is a mixture since it is made up of water molecules and soluble salts

3 0

3 years ago

How can I solve this question.​

How can I solve this question.