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3 years ago

Which statement is true about the electromagnetic spectrum?

1 answer:

6 0

The statement that tells a fact about the electromagnetic spectrum is the third option. Electromagnetic spectrum contains a spectrum of visible light and a wide array of non-visible forms of radiation. Electromagnetic spectrum is a common term for all frequencies and extended wavelengths of electromagnetic radiation or photons.

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33. A basketball bounces on the gym floor nine times and finally comes to a rest. Which of these BEST explains why the

kkurt [141]

The answer is A. good luck.

3 0

3 years ago

What is the overall charge of an ion that has 12 protons, 10 electrons, and 14 neutrons?

kakasveta [241]

The charge of the ion would be +2, because there are 2 more protons than there are electrons. The neutrons don't matter because they have a neutral charge, meaning they are neither positive nor negative.

6 0

2 years ago

A gas evolved during the fermentation of alcohol had a volume of 19.4 L at 17 °C and 746 mmHg. How many moles of gas were collec

AlexFokin [52]

Answer:- 0.800 moles of the gas were collected.

Solution:- Volume, temperature and pressure is given for the gas and asks to calculate the moles of the gas.

It is an ideal gas law based problem. Ideal gas law equation is used to solve this. The equation is:

PV=nRT

Since it asks to calculate the moles that is n, so let's rearrange this for n:

$n=\frac{PV}{RT}$

V = 19.4 L

T = 17 + 273 = 290 K

P = 746 mmHg

we need to convert the pressure from mmHg to atm and for this we divide by 760 since, 1 atm = 760 mmHg

$P=746mmHg(\frac{1atm}{760mmHg})$

P = 0.982 atm

R = $0.0821\frac{atm.L}{mol.K}$

Let's plug in the values in the equation to get the moles.

$n=\frac{0.982atm*19.4L}{0.0821\frac{atm.L}{mol.K}*290K}$

n = 0.800 moles

So, 0.800 moles of the gas were collected.

4 0

3 years ago

You are instructed to create 900. mL of a 0.29 M phosphate buffer with a pH of 7.8. You have phosphoric acid and the sodium salt

Aleksandr [31]

Answer:

B and C

Explanation:

When we have to do a buffer solution we always have to choose the reaction that has the pKa closer to the desired pH value. When we find the pKa values we will obtain:

$pKa_1=-Log[6.9x10^-^3]=2.16$

$pKa_2=-Log[6.2x10^-^8]=7.20$

$pKa_3=-Log[4.8x10^-^13]=12.31$

The closer value is pKa2 with a value of 7.2. Therefore we have to use the second reaction. In which $H_2PO_4^-^1$ is the acid and $HPO_4^-^2$ is the base. Therefore the answer for the first question is B and the answer for the second question is C.

8 0

2 years ago

What does Q=mcdeltaT stand for ?

AVprozaik [17]

Its a formula relating to specific heat capacity

Δθ refers to the change in temperature

Q refers to the energy neededto raise the temperature of an object by the change in temperature

m stands for the mass of tje object

c is the specific heat capacity which is the amount of energy needed to heat up an object per unit mass

4 0

3 years ago