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3 years ago

6th grade science please answer both ! :))

Chemistry

1 answer:

Elanso [62]3 years ago

4 0

Answer:

21. Erosion causes physical changes. For example - Land degradation, deforestation.

20. B statement is closely related to climate.

hope it helps!

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What is the specific heat of a substance if a mass of 10.0 kg increases in temperature from 10.0°C to 70.0°C when 2,520 J of hea

Ksju [112]

Answer:

A. 0.00420 J/(gi°C)

Explanation:

i got it rigt

8 0

3 years ago

Translation: Explain the importance of energy levels,

tigry1 [53]

Answer: Formation of a stable Duplet or Octet structure

Explanation:

Energy levels refers to the definite amount of energies that electrons can have when occupying specific orbitals.

Examples are:

Level 1 as in 1s

Level 2 as in 2s, 2p

Level 3 as in 3s 3p 3d

Level 4 as in 4s 4p 4d 4f

Level 5 as in 5s .......

Level 6 as in 6s .........

Electrons can be excited to higher energy levels by absorbing energy from the surroundings during chemical reactions and so forming chemical bonds like ionic, covalent etc.

A perfect example is Sodium (Na) and Chlorine (Cl) in Sodium chloride (NaCl)

Sodium has atomic number of 11, so energy level is 1s2, 2s2 2p6, 3s1

Chlorine has atomic number of 17, so energy level is 1s2, 2s2 2p6, 3s2 3p5

You will notice that the both Na and Cl, has electrons in the energy level 3. Then, the bond formed must be one that lead to the formation of a OCTET structure: as in Na gives off its 3s1 electron TO Cl.

Thus, Cl now becomes 1s2, 2s2 2p6, 3s2 3p6 - an OCTET STRUCTURE (with completely filled outershell and full energy level 3) in NACl.

So, a duplet or Octet structure is the answer

8 0

3 years ago

One isotope of oxygen differs from another isotope of oxygen in *

Reptile [31]

Each isotope of Oxygen has a different number of neutrons

<h3>Further explanation </h3>

The elements in nature have several types of isotopes

Atomic mass is the average atomic mass of all its isotopes

Isotopes are atoms has the same number of protons but has a different number of neutrons.

So Isotopes are elements that have the same Atomic Number (Proton)

Some of the isotopes of oxygen are:

$\tt _8^{16}O,_8^{17}O,_8^{18}O$

Each isotope has 8 protons and 8 electrons but has a different number of neutrons

For O-16: number of neutrons = 16-8 = 8

For O-17: number of neutrons = 17-8 = 9

For O-18: number of neutrons = 18-8 = 10

4 0

3 years ago

Question 5 why does grinding solid crystals increase the rate of dissolving for a solid solute in water? smaller crystals are mo

My name is Ann [436]

Grinding solid crystals increase the rate of dissolving for a solid solute in water because smaller crystals have more surface area. The solubility of a substance depends on the physical and chemical properties of the solute and solvent as well as the temperature, pressure and the pH of the solution. For example increase in temperature increases the rate at which a solute dissolves in a solvent.

5 0

3 years ago

A substance that produces hydroxide ions when placed in water is a(n) _____.

bekas [8.4K]

Answer: A substance that produces hydroxide ions when placed in water is base.

Explanation:

Bases are the substance: