The name of Earth's single, huge continent from over 250 million years ago is (1 point)

What changes if the degree (amount) of intermolecular bonds of a substance are changed?

elixir [45]

<h2>Answer:</h2>

The correct answers are;

volume of a substance

density of a substance

The volume and the density of the substance depend on inter molecular forces of the substance. So, when we will change the degree of inter molecular forces, whether decrease it or increase it, it will affect the volume and density of a substance.

7 0

4 years ago

Read 2 more answers

What are three physical properties of aluminum foil

timofeeve [1]

Aluminum foil is a metal so it has the typycal properties of metals. These are the three most representative properties of metals that aluminum foil exhibit:


1) It is good conductor of electricity: this property is consequence of the metallic bond, which permits that the outermost electrons of each atom can flow through the entire network of atoms conducting the electricity.


2) Is is good conductor of heat: this other property of metals is due to transmission of vibration that is carried out between neighboring atoms.


3) it is ductile: this property means that the metals can be formed into foils.


Other properties that can be mentioned are: solid at room temperature and mallealble (can form wires)

6 0

3 years ago

Chemistry! Help! Please!

Ratling [72]

Question 1

The correct answer is a.

Explanation

The relationship between $pH$ and $pOH$ is given by

$pH + pOH = 14$ , We can use $pH=-log[H^+]$ and $pOH= -log[OH^-]$ . In a we are given the concentration of [OH] and so we use that to find the pOH, then from pOH we can find the pH.

$pOH= -log [2.4 \times 10^-^2] = 1.62\\\\pH = 14 - 1.62= 12.38$

$b.pH=-log(1.53 \times 10^-^2) = 1.82$

c. HCl is a strong acid so it dissociates to 0.0001 $H^+$ and 0.0001 $Cl^-$ , hence

$pH= -log[0.0001] = 4$

$d.pOH= -log [4.4 \times 10^-9] = 8.36\\\\pH= 14- 8.36 = 5.64$

$a.[OH^-] = 2.4 \times 10^-^2$ has a pH 12.36 which is greater than 7

Question 2

The correct answer is d $O_2(g)$ .

Explanation

This is because solids and liquids do not appear in the equilibrium constant expression. Since $K= \frac{[products]}{[reactants]}$ .

For the equation

$2PbS_(_s_) + 3O_2_(_g_) + C_(_s_) \implies 2Pb _(_s_) + CO_2_(_g_) + SO_2(_g_)$

$K= \frac{[CO_2][SO_2]}{[O_2]}$

Question 3

The correct answer is c

In a molecule the oxidation number are assigned to get the sum of a neutral charge or ion. The overall charge of $SO_4^2^-$ is -2 and in all its compounds oxygen has -2 charge, hence

$S+ 4O = -2\\S+4(-2)=-2\\\implies S= -2 +8 = +6$

Question 4

The correct answer is b. An oxidising agent must gain electrons in a reaction, thus it is the one that undergoes reduction.In order find out what is being reduced we write half reactions for molecules that change their state. $Ag^+$ and $K^+$ are spectactor ions in this reaction.

$Cl_2 + 2e \implies 2Cl^-\\\\NO_2 +H_2O \implies NO_3 +2H^+ +2e\\\\H^+ + OH^- \implies H_2O\\$

In the chloride half reaction $Cl_2$ gains electrons to become $Cl^-$ ions.

Question 5

The last element D is correct. When a nucleus decays by beta emission it produces a daughter nucleus that has same mass number but different atomic number. Therefore beta-decay will have equation

$\frac{187}{75} Re \implies \frac{187}{76} Os + \beta$

Question 6

The correct answer is a. A beta particle is an electron because it has a charge of -1 and has same mass as an electron, while a positron is a particle with the same mass as an electron but with a positive charge.

4 0

3 years ago

A scientist measures a substance to be 0.6 grams. Calculate the percent of error in the measurement.

Thepotemich [5.8K]

Percent error is an expression that is used as a tool for determining the precision of your calculations. It is calculated by the absolute value of the difference of experimental and theoretical values over the theoretical values multiplied by 100%. Hope this helps.

7 0

3 years ago

Gold can be separated from sand by panning or by a sluice-box. In panning, water is mixed with the sand and the resulting slurry

ArbitrLikvidat [17]

Answer:

Decantation by means of difference in relative densities.

Explanation:

The specific gravity (relative density) of the gold to the soil/sand is the physical property exploited in panning gold. The particles with lower density would float whilst the heavier gold sinks lower to the bottom of the pan by gravity and is decanted off.

I hope this explanation is easy to comprehend.

6 0

3 years ago