Identify the anode and cathode please

Answer:

Pb(s) ---> Pb+2 + 2e- is the anode

Cu+2(aq) + 2e- ---> Cu(s) is the cathode

Answer:

b. The substance spilled on his hand is an acid. The base in the soap will neutralize the acid to make it stop burning.

Explanation:

In this case, the substance spilled on the hand is an acid, so it will require neutralization. In neutralization reactions, you have an acid and a base, which will be soap. This reaction is known as saponification.

Answer: A. the age of a layer of rock

Explanation:

Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time.

Index fossils are found throughout the world and come from organisms which existed during the limited periods of geologic time. Index fossils can be used to determine the age of a layer of rock. Thus, the correct option is A.

Index fossil is any kind of animal or plant that is preserved in the rock record of the Earth which is characteristic of a particular span of geologic time. A useful index fossil must be distinctive or is easily recognizable, abundant, and have a very wide geographic distribution and also a short range through time.

Index fossils are used to define the geological periods or the age of a layer of rock. These fossils can be defined as the commonly found, widely distributed fossils that are limited in time span. If a person finds an index fossil in a given layer, then he has bounds on the age of the layer.

Therefore, the correct option is A.

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Answer:

nitrogen

Explanation:

Living organisms often contain trace amounts of several elements, but the most abundant ones are oxygen, carbon, hydrogen, nitrogen, calcium and phosphorus.

Oxygen. ...

Carbon. ...

Hydrogen. ...

Nitrogen. ...

Sulfur. ...

Phosphorus.

The Six most Abundant Elements that occur in Living Organisms.

So the correct answer is option D. Nitrogen.

Nitrogen is important for plant growth and can be 'fixed' by lightning or added to soils in fertilizers. A colourless, odourless gas. Nitrogen is important to the chemical industry. It is used to make fertilisers, nitric acid, nylon, dyes and explosives.

It is used to make amino acids in our body which in turn make proteins. It is also needed to make nucleic acids, which form DNA and RNA. Humans or other species on earth require nitrogen in a 'fixed' reactive form.

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Answer: c

Explanation: an xray wave does have a higher frequency than an infrared wave.

Answer:

Explanation:c

Answer:

A

Explanation:

Neutralization reaction is

base + acid ---> salt + water.

A student determines that she used 0.0665 mole of sodium hydroxide (NaOH) to completely titrate 25.00 mL of sulfuric acid solution. The molarity of the sulfuric acid is 1.31 M. Therefore, option C is correct.

Number of moles of solute per liter of solution is known as molarity.

The balanced chemical equation for the reaction between sodium hydroxide and sulfuric acid is:

2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O

According to the balanced equation, one mole of sulfuric acid reacts with two moles of sodium hydroxide. Therefore, the number of moles of sulfuric acid in the titrated solution can be calculated as:

moles of H₂SO₄ = (moles of NaOH) / 2

moles of H₂SO₄ = 0.0665 mol / 2

moles of H₂SO₄ = 0.03325 mol

The volume of the sulfuric acid solution used in the titration is 25.00 mL, which is equivalent to 0.02500 L. The molarity (M) of the sulfuric acid can be calculated as:

Molarity of H₂SO₄ = moles of H₂SO₄ / volume of H₂SO₄ solution in liters

= 0.03325 mole / 0.02500 L

= 1.31 M

Thus, option C is correct.

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Answer:

A. 16 grams.

B. 4 mol.

Explanation:

A. To find the atomic weight of one mole of CH4, we can simply reference the periodic table and find the atomic weights of each element:

12.0+4(1.0)= 16.0 g.

B. To find the amount of moles in 64 grams, we can simply divide:

64.0÷16.0= 4 mol.

Answer:

c

Explanation:

Answer:

1.84 atm

Explanation:

P2=V1P1/V2

Temp is irrelevant because it is constant, so all you have to do is rearrange the ideal gas law.

You can check this by knowing P and V at constant T have an inverse relationship and therefore makes this the correct answer.

- Hope that helps! Please let me know if you need further explanation.

Answer: conjugate base

Explanation:

According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

A weak acid has a strong conjugate base whereas a strong acid has a weak conjugate base. Similarly a weak base has a strong conjugate acid whereas a strong base has a weak conjugate acid.

[tex]CH_3COOH+NH_3\rightarrow CH_3COO^-+NH_4^+[/tex]

Acetic acid [tex]CH_3COOH[/tex] is weak acid which has strong conjugate base [tex]CH_3COO^-[/tex]

Answer:

D. the physical and chemical properties of the products are different from the reactants

Explanation:

Answer:

[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}Y[/tex]

Explanation:

The unbalanced nuclear equation is

[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e \, + \, ?[/tex]

Let's write the question mark as a nuclear symbol.

[tex]\rm _{38}^{91}Se} \longrightarrow \, _{-1}^{0}e \, + \, _{Z}^{A}X[/tex]

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.  

Then

98 =  0 + A, so A =  98 -  0 = 98, and

38 = -1 + Z, so Z  = 38 + 1 = 39

Then, your nuclear equation becomes

[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}X[/tex]

Element 39 is yttrium, so the balanced nuclear equation is

[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}Y[/tex]

Answer:

 24He

Explanation:

When a nuclide is bombarded with alpha particles, we notice an increase in its mass and charge since an alpha particle has a mass of four and a charge of +2. recall that nuclear equations must be balanced. That is, the masses and charges on the left hand six and the right hand side of the nuclear reaction equation must be exactly the same.

Looking at the nuclear reaction at hand, the total mass on the left hand side has to be 246 while the total charge on the left hand side of the equation will be 98. Coming over to the right hand side, the total masses are also found to be the same as a neutron with no charge and a mass of 1 is produced. Hence the nuclear reaction equation is balanced when an alpha particle (helium nucleus) is substituted for X in the equation.

Answer:

24HE

I took the test!

Answer:

[tex]m = 64\,g[/tex]

Explanation:

The mass of the solute is given by the following expression:

[tex]m = 0.16\cdot (400\,g)[/tex]

[tex]m = 64\,g[/tex]

Answer:

True True False

Explanation:

Valves are in most veins (to prevent backflow). Also valves in the chart and an in an combustion engine.

So the first statement is True.

Valves control the flow rate and direction of fluid within a closed system. So the second statement is True.

1 Pa = 1 N/m² So since 1 Pa equals to one newton per square metre the third statement is False.

When CuSO​4​​⋅​ 5H​2​O is heated in a crucible, there is a loss of water. Subtract the mass of the CuSO​4​⋅ 5H​2​O from the mass of CuSO​4 to determine the amount of water lost. Therefore, option B is correct.

A substance made up of two or more components is called a compound. Table salt, water, and carbon dioxide are a few examples of compounds.

Chemical substances have no electrical charge. In most cases, ionic compounds are created when a metal interacts with a nonmetal. The reaction between two nonmetals produces covalent compounds.

Elements are unadulterated substances made up of only one kind of atom. Compounds are substances that are created when two or more different types of elements are chemically combined in predetermined ratios.

To determine the amount of water lost subtract the mass of the CuSO​4​⋅ 5H​2​O from the mass of CuSO​4.

Thus, option B is correct.

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Answer:

A

Explanation:

Unlike the female reproductive system, the most parts of the male reproductive system are located outside the body. The mentioned part in the given diagram is urethra and it Mixes sperm and semen. The correct option is A.

The male reproductive system includes the testes, scrotum, spermatic ducts, male accessory glands and phallus. All these organs work together to produce sperms, the male gamete, male sex hormones and other components of semen.

The phallus and urethra are the parts of both the reproductive and urinary systems. Scrotum, seminal vesicles, vas deferens, testicles and prostate constitute all the remaining male reproductive system.

The urethra is a tube like structure which is the region included in the urinary tract that takes the urine from the bladder where the semen is ejaculated.

Thus the correct option is A.

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Answer:

butane

Explanation:

Answer:

I'm not entirely sure, but I've heard that vaccines contain very weak amounts of the virus in order to expose your body to it, so that your body can become immune to it before being exposed to the real thing.

So basically, a flu shot contains a weak version of influenza.

I don't know this for sure, but hopefully this helps!

Answer:the objects will be about the same temperature as the room

Explanation:

Answer:

1. (i) H₂ will decrease

(ii) H₂ will increase

2. (i) Shift right

(ii) Shift left

(iii) Shift left

(iv) Shift left

3. (i) Shift left

(ii) Shift right

(iii) Shift left

4. (i) H₂O will increase

(ii) H₂O will increase

Explanation:

1. For the reaction, N₂ (g) + 3H₂ (g) ↔ 2NH₃ (g) + 22 kJ

(i) When the NH₃ is removed, the concentration of the products is reduced favoring the consumption of further reactants hence the H₂ will decrease

(ii) When N₂ is removed, N₂ will become the limiting reactant resulting in the presence of excess H₂, hence H₂ will increase

2. 2NO (g) + H₂ (g) ↔ N₂O (g) + H₂O (g) 36 kJ

(i) When NO is added, it will favor the increase of the reaction and the equilibrium will shift to the right

(ii) H₂ is removed, it will favor the decomposition of the products hence the equilibrium will shift to the left

(iii) When N₂O is added, it will cause the increase in the partial pressure of the products which will result in the increase in the partial pressures of the reactants to compensate, hence the equilibrium will shift to the left

(iv) When H₂ is removed it will cause the equilibrium to shift left as more products will decompose to form the balance H₂

3. For the reaction;

CO₂ (g) + H₂ (g) + heat ↔ CO (g) + H₂O (g)

(i) When CO is added, there will be an excess partial pressure of the products and the equilibrium will shift left

(ii) When CO₂ is added, there will be an excess partial pressure of the reactants which will favor the formation of the products and the equilibrium will shift right

(iii) When H₂ is removed, there will be an decrease in the partial pressure and concentration of the reactants which will favor the decomposition of the products to balance up the partial pressures of the reactant and the equilibrium will shift left

4. In the reaction  2NO (g) + H₂ (g) ↔ N₂O (g) + H₂O (g) + heat

(i) When NO is added, the concentration of the reactants will increase, hence increasing the likelihood of the formation of more products and the equilibrium will shift to the right and H₂O will increase

(ii) When N₂O is removed, the partial pressure and concentration of the products will reduce hence to balance up the partial pressures of the reacting mixture, more products will be formed and H₂O will increase.

Answer:

The abyssal plains

Explanation:

this is because it is so dark and devoid of resources that it is hard for most forms of life to survive

pls make me brainliest :) I'm trying to become an Ace

Answer:

abyssal

Explanation:

Answer:

1 quart of lemonade will be in the first cup

Explanation:

1/4th of a gallon is a quart

Answer:

No.4 is B No.5 is d

Explanation:

Answer:

Q 4: d

Explanation: this is all I can answer

Answer:

1. sublimation

2.melting

3.melting  

4.sublimation

Explanation:

melting is a process when solid changes to liquid

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.

Answer:

c

Explanation:

Answer:

C) indicator like cabbage juice

Explanation:

This is because the pH scale is used to show how acidic or alkaline a substance is. Also it can not be a and b as the sentence doesn't specify the pH nor if it is an acid or a base. This would mean that the sentence would not make sense with a&b.

The pH scale is a scale ranging from 0-14, with 7 being neutral and a number above 7 would be considered alkaline and if the number is less than 7 then it would be considered an acid.

Examples of indicators for the pH scale:

pH probe = a pH probe is a device used to show the pH of a substance.

Universal Indicator= a universal indicator is a substance that changes colour when exposed to a substance. Universal indicator can also show how acidic or alkaline a substance is.

Answer:

D

Explanation:

The safety equipment that is needed when your doing a science experiment you need a safety goggles and gloves.