please help!!! will give brainliest!!! 30 points! (need to put roman numeral in answer)

Answer: Magnets have a force which is known as no contact force. This force tries to attract the metallic objects near it, which makes it move.

Explanation:

Answer:

A. repetition of their physical and chemical properties when arranged according to increased atomic number

Explanation:

There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Therefore, option A is correct option.

Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.

Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.

Periodic law states that elements show a repetition of their physical and chemical properties when arranged according to increased atomic number.

Therefore, the correct option is option A out of given options.

Learn more about periodic table, here:

https://brainly.com/question/11155928

#SPJ2

Answer:

The Earth will stay in motion because it is already moving.

Answer:

b

Explanation:

Answer:

molecule

Explanation:

Answer:

c

Explanation:

Answer:

Metals conduct electricity because they have free Electrons in them which helps the current to move eaisily

Answer:

B-Gamma

Explanation:

Answer:

it is becuse the students used wrong apparatus

The biggest error in this investigation is the use of inappropriate types of equipment.

The types of equipment used in the given setup are inappropriate. Suggested improvements in the apparatus to increase the accuracy are given below:

1. The use of a polystyrene cup in the laboratory for any reaction is inappropriate. As a slight increase in temperature causes the decomposition of the chemicals in the cup as well.

2. The use of a thermometer stand is a must. Without using the stand, the tip of the thermometer touches the lid of the container, which causes inaccuracies in the result.

Hence, all the suggestions are listed above.

Learn more about changes in temperature here:

https://brainly.com/question/31081480

#SPJ2

Answer:

I DO NOT UNDERSTAND THE QUESTION, BUT THANKS FOR THE COINS/TOKENS!

Explanation:

Answer:

the action of magnifying something or the process of being magnified

Answer:

1 : the act of magnifying. 2a : the state of being magnified. b : the apparent enlargement of an object by an optical instrument. — called also power

Answer:

Sorry, i also don't know the answer to this.

Answer:

(I think its mixture not solution)

Explanation:

Multiphase Mixtures

Carbonated water (or carbonated anything) is a multiphase heterogenous mixture, with gaseous carbon dioxide (CO2) bubbling through liquid water (H2O).

Answer: The answer is C. Gas-Liquid

Explanation: I just took the quiz

d. all of the above

AnswerD:

Explanation:

Explanation:

water from rain and snow that travels to streams

Please help!

Water from a rain and snow that travels to streams are examples of run off. These natural processes are part of water cycle and balance the water content in the atmosphere and hydrosphere.

Water cycle is a geological phenomenon to balance the  water content in the atmosphere, hydrosphere and in the biosphere. The water bodies evaporate by the heat radiated by sun.

The air moisture can be restored to the land through the cooling of the vapor and pour as rain. This best illustrates the interaction between atmosphere and hydrosphere.

Rain, snow, sleet, or hail that reaches a surface stream without ever going below the soil's surface is referred to as surface runoff. It differs from direct runoff, which is runoff that directly reaches surface streams following rainfall or snowmelt. Hence option 4 is correct.

Find more on water cycle :

brainly.com/question/1151425

#SPJ6

Answer:

The materials would be best to us for the core to make the strongest electromagnetic to pick up the most nails is described below in detail.

Explanation:

Use a couple of wire strip-pers to exclude some centimeters of insulation from every end of the cable. Skillfully cover the cable around the nail. The more cable you enclose around the nail, the more effective your electromagnet will be. Compose certain that you leave sufficient of the cable unwrapped so that you can connect the battery.

Answer:14.5 grams of K2O

Explanation:

4K(s) + O2(g) → 2 K2O(s). If a staff member at a laboratory has 12.0 grams of potassium metal,  14.5 grams of K2O is the theoretical yield of potassium oxide that the scientist could potentially produce from the reaction with oxygen gas. Therefore, option B is correct.

The yield of a reaction is used to represent how much of a product is produced from that reaction. The theoretical yield is the quantity of product that stoichiometry predicts will be produced, whereas the actual yield is the amount that is actually produced.

Divide the ratio by the limiting reactant's molecular weight. The answer is the theoretical yield of the desired product in moles.

It is useful to know how much product will be created with specific reactant amounts before carrying out chemical reactions. The theoretical yield is what is meant by this. This method can be applied to determine the theoretical yield of a chemical reaction.

Thus, option B is correct.

To learn more about theoretical yield, follow the link;

https://brainly.com/question/175584

#SPJ2

Answer:

312g O₂ son necesarios, se producen 264g CO₂ y 135g H₂O

Explanation:

La combustión de butano para producir CO₂ y H₂O ocurre así:

C₄H₁₀ + 13/2O₂ → 4CO₂ + 5H₂O

Donde 1 mol de butano reacciona con 13 moles de oxígeno para producir 4 moles de dióxido de carbono y 5 moles de agua.

Para resolver este problema debemos convertir la masa de butano a moles y, usando la reacción balanceada, obtener cuánto se necesita de oxígeno y cuánto se produciría de dióxido de carbono y agua:

Moles butano -Masa molar: 58.12g/mol-:

87.0g * (1mol / 58.12g) = 1.50 moles

Moles y masa de oxígeno necesarias para la reacción -Masa molar: 32g/mol-:

1.50 moles C₄H₁₀ * (13/2 moles O₂ / 1 mol C₄H₁₀) = 9.75 moles * (32g/mol) =

312g O₂ son necesarios

Moles y masa de dióxido de carbono producidas -Masa molar: 44.01g/mol-:

1.50 moles C₄H₁₀ * (4 moles CO₂ / 1 mol C₄H₁₀) = 6 moles * (44.01g/mol) =

264g CO₂ se producen

Moles y masa de agua producidas -Masa molar: 18.015g/mol-:

1.50 moles C₄H₁₀ * (5 moles H₂O / 1 mol C₄H₁₀) = 7.5 moles * (18.015g/mol) =

135g H₂O se producen

Answer:

[NaOH] = 0.1 Molar ... Note => the brackets around formula;i.e., "[ ]" is generally accepted in the chemistry community as concentration in Molar terms.

Explanation:

The metathesis rxn, or double replacement rxn, equation is:

(Molarity x Volume) of acid = (Molarity x Volume) of base, or

(M·V)acid = (M·V)base => M(base) = M·V(acid)/V(base)

= 0.1M × 18.3ml / 20ml = 0.0915M(base) = 0.1M (1 sig-fig) = [NaOH]

Explanation:

STEP 1- Take two iron nails.

STEP 2- Clean it with sand paper.

STEP 3- Wrap copper wire around both the nails. And connect the other end to the battery terminal.

STEP 4- Take water in beaker and little amount of salt in it or a few drpos of sulphuric acid in it.

STEP 5- Immerse the nails in the solution.

STEP 6- Observe the nails carefully. You can see bubbles of gases coming out from water near nails.

When, electeric current is passed through water gases like hydrogen and oxygen are evolved.

2.Three things are required in proper combination before ignition and combustion can take place---Heat, Oxygen and Fuel. There must be Fuel to burn. There must be Air to supply oxygen. There must be Heat (ignition temperature) to start and continue the combustion process.

When iron is placed in Copper sulphate solution, the iron is coated with a brown coloured substance "copper" and CuSo4 solution changes from blue to light green. This is due to iron displaces copper as it is more reactive than copper.

Answer:

29.9 g of CO₂ will be produced by the reaction.

Explanation:

This is the reaction:

CaCO₃(s)  + 2HCl (aq)  →  CaCl₂(aq)  + CO₂(g) +  H₂O(l)

First of all, we state the moles of each reactant:

68.1 g . 1mol/ 100.08g = 0.680 mol of carbonate

51.6 g . 1 mol/36.45g = 1.46 mol of acid.

The solid salt is the limiting reactant. Ratio is 2:1

2 moles of acid can react to 1 mol of salt

1.46 mol of acid may react with (1.46 . 1)/2 = 0.727 moles

As we only have 0.680 moles of salt, we do not have enough.

Let's work at the product side. Ratio is 1:1

1 mo of salt can produce 1 mol of gas

0.680 moles will produce 0.680 moles of gas

We convert the moles to mass → 0.680 mol . 44g / 1mol = 29.9 g of CO₂

The number of grams of Co2 should be produced is 29.9 g.

Since

CaCO₃(s)  + 2HCl (aq)  →  CaCl₂(aq)  + CO₂(g) +  H₂O(l)

So,

68.1 g . 1mol/ 100.08g = 0.680 mol of carbonate

51.6 g . 1 mol/36.45g = 1.46 mol of acid.

Now the ratio should be 2:1 for the solid salt

And, there is 2 moles of acid can react to 1 mol of salt

So,

1.46 mol of acid may react with (1.46 . 1)/2 = 0.727 moles

Now the product side the ratio is 1:1

So, that means

1 mo of salt can produce 1 mol of gas

So, the no of grams should be

= 0.680 mol . 44g / 1mol

= 29.9 g of CO₂

Learn more about grams here: https://brainly.com/question/10623774

Answer:

Very sweet tea

Explanation:

yeah... because sweet tea can cause tooth decay in our mouth thats why...(Please check the other answers also...Its all my point of view....thank you)

Answer:

MgO

Explanation:

Answer:

What chapter is this and what grade are you, i can check this for you

Explanation:

Answer:

A. electrons must be parts of the atoms of all elements

Answer:

Element with 6s subshell

Explanation:

Reactivity of an element depends on the electronic configuration and position of element in the periodic table as reactivity increases as we go down the periodic table.

This is so because number of shell increases as move down the periodic table and the last electron is further away from the nucleus.

Element with 6s subshell is the largest among 3s and 4s subshell and has more number of shells so it will react more than 3s and 4s subshell.

Hence, the correct answer is "Element with 6s subshell".

Answer:

shear adhesion

Explanation:

edge

Shear adhesion sticks best when it is pulled down parallel to the surface.

Shear adhesion is defined as the ability  of tape due to which it resists the static forces which are applied in same plane as in backing.It is usually expressed in terms of time required  by a given weight for an amount of tape to become loose  from a vertical plane.

Molecular weight between two entanglements is the controlling factor of shear adhesion. Shear adhesion is affected by the following parameters which areas follows:

1)Tg of adhesive - Shear adhesion increases as Tg rises up to a certain temperature which is less than the room temperature.

2)  Tan delta  minimum value of adhesive- It is found that shear adhesion improves by an increase in tan delta minimum value.

3)Adhesive polarity- It is an important factor which affects adhesion  such as tack,peel and shear.Adhesion performances are improved by introducing polar ingredients in the formulation.

Learn more about shear adhesion,here:

https://brainly.com/question/13385447

#SPJ6

[tex]\displaystyle 40 \ mol \ Al[/tex]

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Stoichiometry

Step 1: Define

[RxN - Balanced] 2Al₂O₃ → 4Al + 3O₂

[Given] 20 mol Al₂O₃

Step 2: Identify Conversions

[RxN] 2 mol Al₂O₃ → 4 mol Al

Step 3: Stoich

Step 4:Check

Follow sig fig rules and round. We are given 1 sig fig.

Since our final answer already has 1 sig fig, there is no need to round.

Answer:

7.28 mol Na2SO4

Explanation:

Since it is already in moles, all we have to do is use a molar ratio

A molar ratio is the proportions of reactants and products using the balanced equation. When writing a mole ratio, the given information must cross out with the right thing.

7.28 mol H2SO4 * 1 mol Na2SO4/1 H2SO4 = 7.28 mol Na2SO4

*notice how the H2SO4 crosses out

Answer:

The effects of supercritical CO2 (SC-CO2) on the microbiological, sensory (taste, odour, and colour), nutritional (vitamin C content), and physical (cloud, total acidity, pH, and °Brix) qualities of orange juice were studied. The CO2 treatment was performed in a 1 litre capacity double-walled reactor equipped with a magnetic stirring system. Freshly extracted orange juice was treated with supercritical CO2, pasteurised at 90°C, or left untreated. There were no significant differences in the sensory attributes and physical qualities between the CO2 treated juice and freshly extracted juice. The CO2 treated juice retained 88% of its vitamin C, while the pasteurised juice was notably different from the fresh juice and preserved only 57% of its vitamin C content. After 8 weeks of storage at 4°C, there was no microbial growth in the CO2 treated juice.

Answer:

The sign of change of heat of solution is positive

Explanation:

The dissolution of AgNO3 in water is represented by the equation;

AgNO3(s) --------> Ag^+(aq) + NO3^-(aq)

We can see from the question that as the temperature was increased from 10° to 20°C the solubility of the solute increased from  170g to 222g per 100g of H2O.

This implies that the solubility of the solute increases with increase in temperature.

If a reaction moves in the forward direction when the temperature is increased, then the reaction is endothermic. If the reaction is endothermic, the sign of change of heat of solution is positive.