Answer: K and Na
Explanation:
Potassium and Sodium have a chemical symbol of K and Na respectively.
They have similar chemical properties because both
- have only one valence electron,
- form univalent positive ion when they donate their lone outermost electron as shown below
Na --> Na+ + e-
K --> K+ + e-
- are good reducing agents
- react with cold water vigorously to liberate hydrogen gas and form alkalis, so they are known as alkali metals.
- K and Na are placed in Group 1 of the periodic table.
Thus, unlike the other pairs given, K and Na, have the most similar chemical properties
Answer: 21 lawns per week
Explanation:
The average weekly rate refers to how many lawns were mowed per week given that 233 were done in 11 weeks.
Rate will be given by;
= Lawns mowed / Weeks taken
= 233 / 11
= 21 lawns per week
Explanation:
This is because gas particles are free to move as they are not held in place by strong molecular forces while particles in a solid are
Answer:
secrete cytotoxic substance which triggers apoptosis of target cell.
Explanation:
Cytotoxic T cells have cell surface receptor which recognizes the antigen present on the receptor of target cell. This interaction initiates the process of killing of target cell.
After interaction cytotoxic t cell release cytotoxic substance called granzyme and perforin. Granzyme triggers apoptosis through the activation of caspases or by making the release of cytochrome c and activation of the apoptosome.
Perforin make pores in the cell and its action is similar to complement membrane attack complex. Therefore cytotoxic substances are released by Tc cells which trigger apoptosis of target cell.
Answer:
1. 25 moles water.
2. 41.2 grams of sodium hydroxide.
3. 0.25 grams of sugar.
4. 340.6 grams of ammonia.
5. 4.5x10²³ molecules of sulfur dioxide.
Explanation:
Hello!
In this case, since the mole-mass-particles relationships are studied by considering the Avogadro's number for the formula units and the molar mass for the mass of one mole of substance, we proceed as shown below:
1. Here, we use the Avogadro's number to obtain the moles in the given molecules of water:
2. Here, since the molar mass of NaOH is 40.00 g/mol, we obtain:
3. Here, since the molar mass of C6H12O6 is 180.15 g/mol:
4. Here, since the molar mass of ammonia is 17.03 g/mol:
5. Here, since the molar mass of SO2 is 64.06 g/mol:
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