ASAP PLEASEE

The symbol for gold is a. go. b. g. c. au. d. au.

Zolol [24]

Au is the symbol for gold. It comes from Latin word for gold, which is Aurunum. Its atomic number is 79.

7 0

3 years ago

Read 2 more answers

Identify which reaction is NOT a chemical reaction. es )

vova2212 [387]

Answer:

You never listed the options

Explanation:

A chemical reaction is a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction.

4 0

3 years ago

Match these items. 1. moles per liter of solution solute 2. spreading out Keq 3. substance being dissolved diffusion 4. general

Degger [83]

Answer:

1. moles per liter of solution - Molarity

2. spreading out - diffusion

3. substance being dissolved- solute

4. general equilibrium constant - Keq

5. the substance doing the dissolving in a solution - solvent

6. solubility product constant - Ksp

Explanation:

Number of moles of substance being dissolved in one liter of solution is defined as molarity

Solute is the substance which is dissolved and solvent is the substance into which the solute is dissolved. For example salt is solute and water is solvent.

Ksp defines the solubility product constant which indicates the equilibrium between a solid and solution and the number of ions of solid required to achieve this equilibrium.

Keq depicts the scenario where reactant and product concentrations are constant in a chemical reaction.

Hence, the correct match is

1. moles per liter of solution - Molarity

2. spreading out - diffusion

3. substance being dissolved- solute

4. general equilibrium constant - Keq

5. the substance doing the dissolving in a solution - solvent

6. solubility product constant - Ksp

8 0

3 years ago

I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19

IRINA_888 [86]

Answer:

A) Sample B has more calcium carbonate molecules

Explanation:

M = Molar mass of calcium carbonate = 100.0869 g/mol

$N_A$ = Avogadro's number = $6.022\times 10^{23}\ \text{mol}^{-1}$

For the 4.12 g sample

Moles of a substance is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}$

Number of molecules is given by

$nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}$

For the 19.37 g sample

$n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}$

Number of molecules is given by

$nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}$

$1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}$

So, sample B has more calcium carbonate molecules.

The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.

7 0

3 years ago

(Please help!)

Inessa [10]

Answer:

B. temperature decreases as altitude increases.

Explanation:

Just like in the lower reaches of the atmosphere, the troposphere, in the mesosphere, temperature decreases as altitude increases.

The mesosphere is the third layer of the atmosphere just above the stratosphere.

It begins at the top of the stratosphere and ends at the mesopause where the thermosphere begins.
The mesosphere is often referred to as the middle layer.

With increasing height, the temperature of the mesosphere decreases significantly. The top of the mesosphere is one of the coldest part of the earth atmosphere. This is as a result of increasing atmospheric cooling by carbon dioxide in this region of the atmosphere.

7 0

3 years ago