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Leya [2.2K]
2 years ago
6

Cells of the immune system are able to respond to the

Chemistry
1 answer:
egoroff_w [7]2 years ago
5 0

Answer:

A) antigens present on the invaders

Explanation:

Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens

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In what block, group, and period on the periodic table can the atom with a 1s22s22p63s23p64s23d104p7 ground-state electron confi
Yanka [14]
No the maximum number of electrons for "4p" is 6 so there can't be a 4p7
7 0
3 years ago
Read 2 more answers
Natural gas burns in air to form carbon dioxide and water, releasing heat. CH4(g)+2O2(g)→CO2(g)+2H2O(g) ΔHrxn = -802.3 kJ.
Olenka [21]

Answer:

1) Minimum mass of methane required to heat 45.0 g of water by 21.0°C is 0.0788 g.

2) Minimum mass of methane required to heat 50.0 g of water by 26.0°C is 0.108 g.

Explanation:

CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g) ,\Delta H_{rxn} =-802.3 kJ

1) Minimum mass of  methane required to raise the temperature of water by 21.0°C.

Mass of water = m = 45.0 g

Specific heat capacity of water = c = 4.18 J/g°C

Change in temperature of water = ΔT = 21.0°C.

Heat required to raise the temperature of water by 21.0°C = Q

Q=mc\Delta T= 45.0 g\times 4.18 J/g^oC\times 21.0^oC

Q = 3,950.1 J = 3.9501 kJ

According to reaction 1 mole of methane on combustion gives 802.3 kJ of heat.

Then 3.950.1 kJ of heat will be given by:

=\frac{3.950.1 kJ}{802.3 kJ}=0.004923 mol

Mass of 0.004923 moles of methane :

0.004923 mol × 16 g/mol=0.0788 g

Minimum mass of methane required to heat 45.0 g of water by 21.0°C is 0.0788 g.

2) Minimum mass of  methane required to raise the temperature of water by 26.0°C.

Mass of water = m = 50.0 g

Specific heat capacity of water = c = 4.18 J/g°C

Change in temperature of water = ΔT = 26.0°C.

Heat required to raise the temperature of water by 21.0°C = Q

Q=mc\Delta T= 50.0 g\times 4.18 J/g^oC\times 26.0^oC

Q = 5,434 J= 5.434 kJ

According to reaction 1 mole of methane on combustion gives 802.3 kJ of heat.

Then 5.434 kJ of heat will be given by:

=\frac{5.434 kJ}{802.3 kJ}=0.006773 mol

Mass of 0.006773 moles of methane :

0.006773 mol × 16 g/mol= 0.108 g

Minimum mass of methane required to heat 50.0 g of water by 26.0°C is 0.108 g.

6 0
4 years ago
????how many students failed this science class???
deff fn [24]

Answer:

B

Explanation:

You take the 50-69 and you add up the students and it will allow you to get 7

6 0
3 years ago
Which are NOT vascular seedless plants?
erastovalidia [21]

You didn't give options but seedless vascular plants are plants that contain vascular tissue, but do not produce flowers or seeds so for example ferns and horsetails

6 0
3 years ago
Please help me!! i will give branliest to the best answer
Komok [63]

Answer:that answer is b

Explanation:

8 0
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