Explain the difference between biotic and abiotic

The density of magnesium is 1.7 g/cm3, and the density of iron is 7.9 g/cm3. Consider a block of iron with a mass of 819 g. What

BigorU [14]

Answer:

mass of Mg=0.016g

Explanation:

P(Mg)=1.7g/cm³

P(Fe)=7.9g/cm³

m(Fe)=819g

P(Fe)=m(Fe)/v(Fe)

7.9=819/v(Fe)

v(Fe)=0.0096cm³

since v(Mg)=v(Fe)

=0.0096cm³

P(Mg)=m(Mg) /v(Mg)

1.7=m(Mg)/0.0096

m(Mg) = 0.016g

8 0

2 years ago

Which of the following best describes a non metal

Andre45 [30]

Answer:

-a nonmetal is a substance that lacks the characteristics of a metal.

-Seventeen elements are generally classified as nonmetals: most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine); and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).

6 0

3 years ago

Read 2 more answers

Calculate (a) the number of moles of hydrogen required to react with 0.0969 moles of nitrogen, and (b) the number of moles of am

Bumek [7]

Answer:

The answer to your question is:

Explanation:

Data

moles H=?

moles of N = 0.0969

moles of NH₃=?

N₂ (g) + 3 H₂ (g) ⇒ 2NH₃ (g)

Process

1.- Set a rule of three to calculate the moles of hydrogen

1 mol of nitrogen ------------- 3 moles of hydrogen

0.0969 moles of N ---------- x

x = (0.0969 x 3) / 1

x = 0.2907 moles of hydrogen

2.- Set a rule of three to calculate the moles of ammonia

1 mol of nitrogen -------------- 2 moles of ammonia

0.0969 mol of N -------------- x

x = (0.0969 x 2) / 1

x = 0.1938 moles of ammonia

5 0

3 years ago

The specific spatial arrangement of amino acid residues that are close to each other in the polypeptide chain is called______the

natulia [17]

Answer:

c. tertiary.

Explanation:

In this case, we can review the definition of each level of structuration in the proteins:

Primary structure

In the primary structure, the amino acids are linked by peptide bonds. That is, the order of the amino acids is the criterion that defines this type of structure.

Secondary structure

In the secondary structure, we have to look at the way in which the protein is folded. The options are:

-) Beta-laminar: A structure in which the protein has a planar shape.

-) Alpha-helix: A structure in which the protein has a cross-strand form.

Tertiary structure

In the tertiary structure, the R groups that the amino acids have in the primary structure can generate interactions with each other. Interactions such as hydrogen bridges, dipole-dipole, hydrophobic interactions. This makes the protein have a very specific three-dimensional structure, on which its function depends.

Quaternary structure

In the quaternary structure, several subunits may be attached, or there may be prostatic groups (metals that can help to attach various protein units).

With all these in mind, the deffinition that fits with the description in the question is the tertiary structure.

I hope it helps!

4 0

2 years ago

How many moles are in 2.8x10^24 atoms of silicon?

sergejj [24]

Answer:

4.6 mol Si

General Formulas and Concepts:

Atomic Structure

Reading a Periodic Table
Moles
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

Using Dimensional Analysis

Explanation:

Step 1: Define

[Given] 2.8 × 10²⁴ atoms Si

[Solve] moles Si

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

[DA] Set up: $\displaystyle 2.8 \cdot 10^{24} \ atoms \ Si(\frac{1 \ mol \ Si}{6.022 \cdot 10^{23} \ atoms \ Si})$
[DA] Divide [Cancel like units]: $\displaystyle 4.64962 \ mol \ Si$

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

4.64962 mol Si ≈ 4.6 mol Si

6 0

2 years ago