All categories

3 years ago

Which structures are part of the body's first line of defense against pathogens?

1 answer:

7 0

“A” white blood cells. They are the first line of defense against pathogens. They help protect your body and help the pathogens to not spread.

I hope this helps!
~kaikers

You might be interested in

16. Nuclear decay is a random event and

12345 [234]

Answer:

A. Is independent of other energy influences

Explanation:

Nuclear decay occurs at a constant rate. The rate of decay is independent of temperature.

B, C, and D are wrong. The decay rate cannot be sped up or slowed down at ordinary temperatures.

4 0

4 years ago

Volcanoes emit much hydrogen sulfide gas, h2s, which reacts with the oxygen in the air to form water and sulfur dioxide, so2. ev

liq [111]

Answer: There will be 131.3 tons of $SO_{2}$ that will be generated.

Explanation : We have the data as 72 tons of $H_{2}S$ , $O_{2}$ is 101 tons and $H_{2}O$ as 38 tons.

Conversion of 1 ton to kg will be approximately 907.2 Kg

We have to convert the given data of tons into kg for all;

So, moles of $H_{2}S$ = (72 tons X 907.2 Kg/ton X 1000 g/Kg) / (34.082 g/ mol) = 1.916 X $10^{6}$ moles

Now, moles of $O_{2}$ = (101 tons X 907.2 Kg/ton X 1000 g/Kg) / (32 g/mol) = 2.80 X $10^{6}$ moles

And, $H_{2}O$ = (38 tons X 907.2 Kg/ton X 1000 g/Kg) / (18.016 g/mol)

= 1.03 X $10^{6}$ moles

Now, we have to calculate the moles of $H_{2}S$

so, 1.916 X $10^{6}$ moles / 2 moles of $H_{2}S$ = 958 X $10^{3}$

Now, for $O_{2}$ ;

So, 2.80 X $10^{6}$ moles / 3 moles of $O_{2}$ = 933.3 X $10^{3}$ moles

Here, we can see that $O_{2}$ is acting as a limiting reactant.

Now, moles of $SO_{2}$ = 2.80 X $10^{6}$ X (2 moles of $SO_{2}$ / 3 moles of $O_{2}$ ) = 1.86 X $10^{6}$

Now converting this into mass,

Mass = Moles X Molar Mass

Mass = 1.86 X $10^{6}$ X (64.066 g/mol X $10^{-3}$ kg/g) X (1 ton / 907.2 Kg)

= 131.3 tons of $SO_{2}$

7 0

3 years ago

Read 2 more answers

Please someone help I’m really confused

NARA [144]

Answer:10-3

Explanation:

7 0

3 years ago

You measure 2.34 g of K2Cr2O7 into a volumetric flask. You dilute the K2Cr2O7 with water to a volume of 250 mL. It takes 35.7 mL

natta225 [31]

Answer:

0.191M of Na₂C₂O₄ is the concentration of the original Na₂C₂O₄ solution

Explanation:

The reaction of potassium dichromate, K₂Cr₂O₇ with sodium oxalate, Na₂C₂O₄ in the presence of acid H⁺ is:

K₂Cr₂O₇ + 3Na₂C₂O₄ + 14H⁺ → 2Cr³⁺ + 6CO₂ + 7H₂O + 6Na⁺ + 2K⁺

<em>Thus, 1 mole of K₂Cr₂O₇ reacts with 3 moles of Na₂C₂O₄</em>

Moles of 2.34g of K₂Cr₂O₇ (Molar mass: 294.185g/mol):

2.34g K₂Cr₂O₇ ₓ (1mol / 294.185g) = 7.954x10⁻³ moles K₂Cr₂O₇

In 250mL = 0.250L:

7.954x10⁻³ moles K₂Cr₂O₇ / 0.250L = 0.0318M K₂Cr₂O₇

Moles in 35.7mL = 0.0357L of this solution are:

0.0357L ₓ (0.0318mol / L) = <em>1.136x10⁻³ moles K₂Cr₂O</em>₇ in solution. As 1 mole of K₂Cr₂O₇ reacts with 3 moles of Na₂C₂O₄, to titrate the moles of K₂Cr₂O₇ in solution you need:

1.136x10⁻³ moles K₂Cr₂O₇ × (3 moles Na₂C₂O₄ / 1 mole K₂Cr₂O₇) =

<em>3.408x10⁻³ moles of Na₂C₂O₄</em>

In 17.8mL = 0.0178L:

3.408x10⁻³ moles of Na₂C₂O₄ / 0.0178L =

<h3>0.191M of Na₂C₂O₄ is the concentration of the original Na₂C₂O₄ solution</h3>

<em />

3 0

3 years ago

A mass spectrometer is being used to monitor air pollutants. It is difficult, however, to separate molecules with nearly equal m

tatyana61 [14]

Answer:

4.2 m

Explanation:

The energy (E) of the selector region of the spectrometer is:

E = v*B (equation 1)

Where v is the velocity, and B the magnetic field.

The force with which particle forms a curved path can be calculated by:

$\frac{mv^2}{r} = qB'$

Where r is the radius of the particle, m is the mass, and q the electric charge. So:

$r = \frac{mv}{qB'}$

For equation 1: v = E/B, so:

$r = \frac{mE}{qBB'}$

The two species will be separated by Δr = 0.42 mm

Δr = Δm*E/(q*B*B')

E/(q*B*B') = r/m

Δr = Δm*r/m

r = m*Δr/Δm

r is the large of curvature, m is the avarege mass = (28.0106 + 28.0134)/2 = 28.012:

r = (28.012*0.42)/(28.0134 - 28.0106)

r = 11.76504/(0.0028)

r = 4201.8 mm

r = 4.2 m

3 0

3 years ago