The positively charged particles found in the nucleus of an atom are called _____

Calculate the number of atoms of H in 22.5g of H2O

Marta_Voda [28]

2.5gm answer ....2/18x22.5

3 0

3 years ago

Explain how nutrients are cycled in a food chain.

Ksenya-84 [330]

Answer:By their movement, by their wastes, and by their metabolic.

Explanation:The nutrient cycle is a system where energy and matter are transferred between living organisms and non-living parts of the environment. This occurs as animals and plants consume nutrients found in soil, and these nutrients are then released back into the environment via death and decomposition.

8 0

3 years ago

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Calculate the number of hydrogen atoms present in 40g of urea, (NH2)2CO

tekilochka [14]

Answer: There are $16.14 \times 10^{23}$ atoms of hydrogen are present in 40g of urea, $(NH_{2})_{2}CO$ .

Explanation:

Given: Mass of urea = 40 g

Number of moles is the mass of substance divided by its molar mass.

First, moles of urea (molar mass = 60 g/mol) are calculated as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol$

According to the mole concept, 1 mole of every substance contains $6.022 \times 10^{23}$ atoms.

So, the number of atoms present in 0.67 moles are as follows.

$0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms$

In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.

$4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms$

Thus, we can conclude that there are $16.14 \times 10^{23}$ atoms of hydrogen are present in 40g of urea, $(NH_{2})_{2}CO$ .

7 0

3 years ago

Which best explains why the trend in noble gas boiling points increases down the group?A) increasing dispersion interactions B)

zhenek [66]

Answer:

A) increasing dispersion interactions

Explanation:

Polarizability allows gases containing atoms or nonpolar molecules (for example, to condense. In these gases, the most important kind of interaction produces dispersion forces, attractive forces that arise as a result of temporary dipoles induced in atoms or molecules.

Dispersion forces, which are also called London forces, usually increase with molar mass because molecules with larger molar mass tend to have more electrons, and dispersion forces increase in strength with the number of electrons. Furthermore, larger molar mass often means a bigger atom whose electron distribution is more easily disturbed because the outer electrons are less tightly held by the nuclei.

Because the noble gases are all nonpolar molecules, the only attractive intermolecular forces present are the dispersion forces.

8 0

3 years ago

The shape and surface texture of aggregate particles is important for both Portland cement concrete (PCC) and hot mix asphalt (H

BartSMP [9]

Answer:

Rough and angular aggregate is preferred

Explanation:

The ideal shape for HMA and PCC is different because aggregates serve different purposes in each material.

In PCC, where aggregates are used as an inexpensive high-strength material to occupy volume, workability is the major issue regarding particle shape. Therefore, in PCC, rounded particles are better as they provide this important feature by virtue of their coarse surfaces and larger surface areas

7 0

3 years ago

The positively charged particles found in the nucleus of an atom are called ______.