The energy needed to melt 1 g of a substance is called the

What is the difference between alkali metals and halogens?

Airida [17]

<h3>→soft and reactive metals. </h3>

Explanation:

<h3>Alkali metals are soft and reactive metals. They react vigorously with water and become more reactive. And other hand halogens are reactive non metals. ... Halogens can be solid, liquid, gaseous at room temperature and the melting point increase when they get bigger.</h3>

<h2>#CAREYINGTOLEARN❤️</h2>

4 0

2 years ago

Read 2 more answers

A sample of xenon occupies a volume of 736 mL at 2.02 atm and 1 °C. If the volume is changed to 416 mL and the temperature is ch

kozerog [31]

Answer:

$\large \boxed{\text{4.63 atm}}$

Explanation:

To solve this problem, we can use the Combined Gas Laws:

$\dfrac{p_{1}V_{1} }{n_{1}T_{1}} = \dfrac{p_{2}V_{2} }{n_{2}T_{2}}$

Data:

p₁ = 2.02 atm; V₁ = 736 mL; n₁ = n₁; T₁ = 1 °C

p₂ = ?; V₂ = 416 mL; n₂ = n₁; T₂ = 82 °C

Calculations:

(a) Convert the temperatures to kelvins

T₁ = ( 1 + 273.15) K = 274.15 K

T₂ = (82 + 273.15) K = 355.15 K

(b) Calculate the new pressure

$\begin{array}{rcl}\dfrac{p_{1}V_{1}}{n_{1} T_{1}} & = & \dfrac{p_{2}V_{2}}{n_{2} T_{2}}\\\\\dfrac{\text{2.02 atm}\times \text{736 mL}}{n _{1}\times \text{274.15 K}} & = &\dfrac{p_{2}\times \text{416 mL}}{n _{1}\times \text{355.15 K}}\\\\\text{5.423 atm} & = &1.171{p_{2}}\\p_{2} & = & \dfrac{\text{5.423 atm}}{1.171}\\\\ & = & \textbf{4.63 atm} \\\end{array}\\\text{The new pressure will be $\large \boxed{\textbf{4.63 atm}}$}}$

6 0

2 years ago

Question

Nonamiya [84]

Answer:

1.7 mL

Explanation:

start with formula M1V1=M2V2

then plug in values (3)V1=(100)(.05) and solve for V1

V1= 1.66

5 0

2 years ago

Assume the recommended single dose of an antihistamine for a child weighing 36–47 lbs is 1.50 teaspoons (tsp) . If 1.00 tsp cont

Scilla [17]

Answer:

18.75 milligrams of active ingredient is the recommended dose for a child weighing 36–47 lbs .

Explanation:

Recommended dose of an antihistamine for a child weighing 36–47 lbs = 1.50 tsp

1 table spoon of antihistamine has 12.5 mg per 5 mL of dose.

Amount of dose in 1 teaspoon = $\frac{12.5 mg}{5 mL}=2.5 mg/mL$

Volume of 1 tsp = 5 ml

Volume of 1.50 teaspoon = $5 mL\times 1.50 =7.50 mL$

Amount of antihistamine in 7.50 mL :

$=2.5 mg/mL\times 7.50 mL=18.75 mg$

18.75 milligrams of active ingredient is the recommended dose for a child weighing 36–47 lbs .

3 0

3 years ago

Julie's science teacher asked her to use quantitative observation to distinguish between 3 metal cylinders to identify aluminum,

SVETLANKA909090 [29]

Since the teacher has said to use quantitative observation, density is the easiest measurement to make. Aluminum has a density of 2.7 g/mL. Brass has a density of 8.73 g/mL. Copper has a density of 8.96 g/mL. As long as the mass and volume measurements are accurate (water displacement can be used for volume measurements), the resulting density values can be distinguished.

It may be possible to distinguish these three metals visually, based on color, but the instructions have stated to use quantitative observation.

8 0

2 years ago