I need help with question 5 whoever helps could get Brainlest or extra credit

What is the pattern of valence numbers on the periodic table?

const2013 [10]

Answer:

In general, the number of valence electrons is the same within a column and increases from left to right within a row. Group 1 elements have just one valence electron and group 18 elements have eight, except for helium, which has only two electrons total.

7 0

3 years ago

If you combine 290.0 mL 290.0 mL of water at 25.00 ∘ C 25.00 ∘C and 140.0 mL 140.0 mL of water at 95.00 ∘ C, 95.00 ∘C, what is t

Alexxandr [17]

Answer:

The final temperature is 47.79 °C

Explanation:

Step 1: Data given

Sample 1 has a volume of 290.0 mL

Temperature of sample 1 = 25.00 °C

Sample 2 has a volume of 140.00 mL

Temperature of sample 2 = 95.00 °C

Step 2: Calculate the final temperature

Heat lost = heat gained

Qlost = -Qgained

Q = m*c* ΔT

Q(sample1) = -Q(sample2)

m(sample1) * c(sample1) * ΔT(sample1) = -m(sample2)*c(sample2) *ΔT(sample2)

⇒with m(sample1) = the mass of sample 1 = 290.0 mL * 1g/mL = 290 grams

⇒with c(sample 1) = the specific heat of water = c(sample 2)

⇒with ΔT(sample 1) = the change of temperature = T2 - T1 = T2 - 25.00 °C

⇒with m(sample2) = the mass of sample 2 = 140.0 mL * 1g/mL = 140 grams

⇒with c(sample2) = the specific heat of water = c(sample1)

⇒with ΔT(sample2) = T2 -T1 = T2 - 95.00°C

m(sample1) * ΔT(sample1) = -m(sample2)*ΔT(sample2)

290 *(T2-25.0) = -140 *(T2 - 95.0)

290 T2 - 7250 = -140 T2 + 13300

430 T2 = 20550

T2 = 47.79 °C

The final temperature is 47.79 °C

4 0

3 years ago

The reaction is found to be first order in IO3−, first order in SO32−, and first order in H+. If [IO3−]=x, [SO32−]=y, and [H+]=z

ollegr [7]

Answer:

rate = kxyz

Explanation:

It is worth knowing that the rate low can only be determined by experimentation only not by just balancing equations. So here we are told that all the reactants x , y and z are all first order. This is important because we use this as exponents. That is why the exponents of all the reactants will be 1.

rate = kxyz

7 0

3 years ago

When you get into a parked car in the summer time, the metal clip is hot and the seat belt fabric is not. What has a higher spec

Helen [10]

The fabric is not a conductor, so it cant store heat, the metal clip is a conductor, so it stores the heat from the sun and when you touch it, it transfers to you. Have a nice day!

4 0

3 years ago

If a gas is compressed from 4L to 1L, and the temperature remains constant, what happens to the pressure?

Bas_tet [7]

USING BOYLE'S LAW PRESSURE BECOMES 4 TIMES WHEN GAS IS COMPRESSED WITHOUT TEMPERATURE CHANGE.

Explanation:

In a container having 4L there are bunch of molecules bouncing around walls and this movement of molecules indicates pressure in the container.

Logically to see when the gas is compressed from 4L to 1L it shows the increased amount of pressure over the container as the number of gas molecules increased and the collisions also increase as the container is same and pressure increases.

Use the equation:

(P1 * V1) / T1 = (P2 * V2) / T2

now cross-multiplying to get

P1 * V1 * T2 = P2 * V2 * T1

Replace V1 with 4L and V2 with 1L. Also, Temperature remains constant, so taking it out of the equation

P1 * 4L = P2 * 1L

Divide both sides by 1L:

P1 * 4 = P2

So the end pressure will be 4 times the beginning pressure.

3 0

3 years ago