Someone plz help me giving brainliest m

Answer:

Four seasons occur on Earth

Explanation:

When the Earth has completely one revolution around the Sun, then it has completed 1 year, and four seasons have occurred in the meantime.

Four seasons occur on Earth when the Earth completes a revolution around the Sun.

The following points can be considered:

Therefore the correct answer is Four seasons occur on Earth.

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Answer:

white

Explanation:

Answer:

250mL, 125mL, 175mL

Explanation:

The beaker has graduated marks every 25mL after the 50mL mark.

Answer:

250ml 125ml 175ml and also do you attend GOC ?

cause same lol

Explanation:

Answer:

b.troposphere

Explanation:

pls mark me brainliest

Answer:

15815.52 kJ

Explanation:

Answer:

2

Explanation:

2×2

2O

soooo

2H2O means 4H2O

Answer:

Density=mass/volume

= 570/2280

=0.25g/ml

Answer:

Explanation:

Data are the facts, figures, and other evidence gathered through observations.

Answer:

The empirical formula is the simplest form;

Given:

Oxygen O at 94.1% and

H at 5.9%

Assume 100grams.

94% = 0.941 x 100gm. = 94.1 gm x 1mole/16gm. = 5.88 moles of O

5.9% = 0.059 x 100gm. = 5.9gm. X 1moleH/1.002gm. = 5.88 moles of H

There is one mole of O for each mole of H so the empirical formula is [tex]O_1H_1[/tex]

and written as OH.

Explanation:

[tex]given \: that \: oxygen \: by \: 94.1\% (.941)\\ hydrogen \: by5.9\%(.059) \\ in \: 100gram \: \\ oxygen = 100 g\times .941 = 94.1 \times \frac{1(mol)}{16g} \\ = 5.88moles \: of \: oxygen \\ in \: hydrogen \: = .059\times 100 = 5.9 \times \frac{1mol}{1.002gram} \\ = 5.88mole \: of \: hydrogen \\ \: so \: here \: \: both \: oxygen \: andhydrogen = 5.88 \\their \: ratio = 1 \: 1 \\ so \: emparical \: formula = oh \\ thank \: you[/tex]

Answer:

oooooooooougifufofhhdykddykyd

Answer:

Historically,Tamil Nadu is known for its temple tanks and community tanks that not only save water for summer but also act as artifical ground water recharge structures. It also set an example by making rain water harvesting mandatory in all building. But now water crisis associated with monsoon failure for consecutive years had lead it to a desperate situation.

Answer:

density is the sum of the mass and volume of an object

The number of moles of reactants and products can be used to obtain the mass of products formed. The results obtained are as follows;

The question says that HCl was in excess. It means that after the reaction, we will have unreacted HCl(aq) and  ZnCl2(aq) in the remaining solution.

Hence;

Mass of ZnCl2(aq) formed = 36.309g - 35.123g  = 1.186g

Number of moles ZnCl2(aq) formed = [tex]\frac{mass of ZnCl2(aq) formed}{molar mass of ZnCl2}[/tex]

[tex]\frac{1.186g}{136.286 g/mol}[/tex] = 0.0087 moles

From the reaction equation;

[tex]Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)[/tex]

To obtain the amount of Zn reacted

1 mole of Zn yields 1 mole of ZnCl2

x moles of Zn yields 0.0087 moles of ZnCl2

x = 0.0087 moles of Zn

a) 1 mole of Zn yields 1 mole of H2

0.0087 moles of Zn yields 0.0087 moles of H2

Mass of H2 = 0.0087 moles of H2 * 2 g/mol = 0.0174 grams

b)

Mass of Zn reacted =  0.0087 moles of Zn * 65.38 grams/mole = 0.5688 grams

c)

Percentage of Zn in the alloy = 0.5688 grams/1.203g * 100 = 47.3 %

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Answer:

Friction always slows a moving object down. ... Friction can be a useful force because it prevents our shoes slipping on the pavement when we walk and stops car tyres skidding on the road. When you walk, friction is caused between the tread on shoes and the ground. This friction acts to grip the ground and prevent sliding.

Answer:

A law which states that if a body is acted upon by two vectors represented by two sides of a triangle taken in order, the resultant vector is represented by the third side of the triangle.

Explanation:

The product of a chemical reaction is what is remaining at the end of the reaction. The combination between reactant to form products can happen in a variety of ways including combination of ions in a solution to form new compounds

The correct compounds representing the variables and the net ionic equations are as follows:

a) A = NaCl

B = H₂O

Balanced net ionic equation: OH⁻(aq) + H⁺(aq) → H₂O (l)

ΔHrxn = Negative

b) C = NH₃

D = NaCl(aq)

E = H₂O(l)

Balanced net ionic equation: OH⁻(aq) + NH₄⁺(aq) → NH₃(aq) + H₂O(l)

ΔHrxn = Negative

c) F = NH₄Cl(aq)

Balanced net ionic equation: H⁺(aq) + NH₃(aq) → NH₄⁺(aq)

ΔHrxn = Negative

The reason the above values are correct are as follows:

a) Part (i)

The given chemical equation is

NaOH(aq) + HCl(aq) → A(aq) + B(l)

The chemical equation is the reaction between sodium hydroxide NaOH (aq) and hydrochloric acid HCl (aq), the product of the reaction is sodium chloride and water as follows;

NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l) + Heat

Therefore, we have;

A = NaCl, and B = H₂O

Part (ii)

The ionic equation is given as follows;

Na⁺(aq) + OH⁻(aq) + H⁺(aq) + Cl⁻(aq) → Na⁺(aq) + Cl⁻(aq) + H₂O (l)

Given that Na⁺(aq) and Cl⁻(aq) are spectator ions in the reaction, we have the balanced net ionic equation given as follows;

Balanced net ionic equation: OH⁻(aq) + H⁺(aq) → H₂O (l)

Part (iii)

ΔHrxn = Negative

b) Part (i)

The given chemical equation is NaOH(aq) + NH₄Cl(aq) → C(aq) + D(aq) + E(l)

The given reaction is between sodium hydroxide, NaOH(aq) and ammonium chloride, NH₄Cl(aq) and the products of the reaction are dissolved ammonia NH₃(aq), sodium chloride NaCl(aq), and water H₂O(l)

Therefore, we have;

NaOH(aq) + NH₄Cl(aq) → NH₃(aq) + NaCl (aq) + H₂O(l) + Heat

Therefore;

C = NH₃, D = NaCl(aq), E = H₂O(l)

Part (ii)

The ionic equation for the reaction is given as follows;

Na⁺(aq) + OH⁻(aq) + NH₄⁺(aq) + Cl⁻(aq) → NH₃(aq) + Na⁺(aq) + Cl⁻(aq) + H₂O(l)

The Na⁺(aq) and Cl⁻(aq) occur in both the reactants and products, therefore, they cancel out as spectator ions and we have;

Balanced net ionic equation: OH⁻(aq) + NH₄⁺(aq) → NH₃(aq) + H₂O(l)

Part (iii)

ΔHrxn = Negative

c) Part (i)

HCl(aq) + NH₃(aq) → F(l)

The given reaction is between hydrochloric acid and aqueous ammonia which has the product as ammonium chloride, NH₄Cl

Therefore, the reaction is given as follows;

HCl(aq) + NH₃(aq) → NH₄Cl(aq) + Heat

∴ F = NH₄Cl(aq)

Part (ii)

The ionic equation is given as follows;

H⁺(aq) + Cl⁻(aq) + NH₃(aq) → NH₄⁺(aq) + Cl⁻(aq)

Therefore, the chlorine ion Cl⁻(aq) occurs in both the reactant and product and can therefore, can be canceled out, and we have;

Balanced net ionic equation: H⁺(aq) + NH₃(aq) → NH₄⁺(aq)

Part (iii)

ΔHrxn = Negative

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Answer:

13.8g

Explanation:

Remember that density is equal to mass over volume

d=m/v

rearrange the problem and you get dv=m

(0.92g/mL)(15mL)=13.8g

Answer:

~58.3 mL

Explanation:

m1*v1=m2*v2 --> (12.0 M HCL) * v1 = 350mL * 2.0M HCL

--> 350*2.0 = 700

--> 700/12.0 M HCL = 58.3 mL repeating

Answer:

D

Explanation:

its a very old study and philosophy of how to change basic substances such as metals into other substances

Answer: yes

Explanation:

While burning fossil fuels energy is under going a chemical reaction but the matter/energy itself is not being destroyed or created

Answer:

The law of conservation applies to the burning fossil fuels

Explanation:

When you burn fossil fuels, some of the energy is transformed into other types of energy, and some of it is transferred to other objects, yet the energy is neither destroyed or created, so it applies to the law of conservation.

Answer:

you tilt the cylinder at a slight angle so that the metal slides down the sides, rather than drops all it`s weight to the bottom

Answer:

it's yellowish in color plz Mark me as brainliest

Answer:

It's a yellowish color like copper

Answer:

[tex]\boxed {\boxed {\sf 6.4 \ atm}}[/tex]

Explanation:

We are asked to find the pressure of a gas in a can given a change in temperature. We will use Gay-Lussac's Law, which states the pressure of a gas is directly proportional to the temperature. The formula for this law is:

[tex]\frac {P_1}{T_1}= \frac {P_2}{T_2}[/tex]

Initially, the gas in the aerosol can has a pressure of 3.10 atmospheres at a temperature of 25 degrees Celsius.

[tex]\frac { 3.10 \ atm}{25 \textdegree C}=\frac{P_2}{T_2}[/tex]

The temperature is increased to 52 degrees Celsius, but the pressure is unknown.

[tex]\frac { 3.10 \ atm}{25 \textdegree C}=\frac{P_2}{52 \textdegree C}[/tex]

We are solving for the new pressure, so we must isolate the variable [tex]P_2[/tex]. It is being divided by 52 degrees Celsius. The inverse operation of division is multiplication, so we multiply both sides of the equation by 52 °C.

[tex]52 \textdegree C *\frac { 3.10 \ atm}{25 \textdegree C}=\frac{P_2}{52 \textdegree C} * 52 \textdegree C[/tex]

[tex]52 \textdegree C *\frac { 3.10 \ atm}{25 \textdegree C}=P_2[/tex]

The units of degrees Celsius cancel.

[tex]52 *\frac { 3.10 \ atm}{25}=P_2[/tex]

[tex]52 *0.124 \ atm = P_2[/tex]

[tex]6.448 \ atm = P_2[/tex]

The original values of pressure and temperature have 2 and 3 significant figures. Our answer must be rounded to the least number of sig figs, which is 2. For the number we calculated, that is the tenths place. The 4 in the hundredth place tells us to leave the 4 in the tenths place.

[tex]6.4 \ atm \approx P_2[/tex]

The gas pressure in the can at 52 degrees Celsius is approximately 6.4 atmospheres.

Answer:

that would be B

Explanation:

Answer:

1, just I) color.

Explanation:

Physical properties are the properties that can be observed without changing the composition of a substance, such as color, temperature, density, and boiling point.

A physical change is a change in the substance that only modifies its aggregation state, such as solidification, and boiling.

Chemical properties are the properties that need a reaction to being observed, such as combustibility, which needs a combustion reaction to being quantified.

When a chemical reaction occurs, and the composition of the substance change, it's a chemical change.

So, heating copper with carbon is a chemical reaction, and purification by electrolysis is too. Color is the only physical property.

Answer:

1). 1 litre

2).12 cm

Explanation:

In 1 litre = 1000 ml whereas 1500 milliliters equals 0.15 litres and it is same for 12 cm and 12 milliliters

Answer:

B bcx is a way of separating different crystals from each other and the other is a way of separating different crystals from each other and the other

Answer:

a.

84,791 » 8479

b.

256.75 » 256.8

c.

431,801 » 4318

d.

0.00078100 » 0.0007810

Explanation:

[tex].[/tex]