老爺子

math help please?

Chemistry  Help ?

The reactant concentration in a first-order reaction was 7.10×10−2 M after 30.0 s and 6.00×10−3 M after 60.0 s . ?

please help with the last 2?

Compute the wavelength of an X-ray with a frequency of 7.0 1018 Hz.?

Factor Theorem Algebra Questions?

What is the rate constant at 250K? Please Help?

what is the distance between P and the position of the ball strike the wall?u is 20ms-1 and the angle is 40 degree?

The graph of y=ax²+c has its vertex at (0,4) and passes through the point (3,-5). Find the value of a.?

If the graph of y = |x| is translated so that the point (1, 1) is moved to (4, 1), what is the equation of the new graph?

pls help asap?

How do I prove tan(theta/2)= sin(theta)/1+cos(theta) for theta in quadrant one?

Please help answer?

Calculus HW help!?

If 4.2 moles of Bromine reacts with excess sodium iodide, how many moles of sodium bromide will be produced?

What is the magnitude of the potential difference across the 5- resistor?

Which of the following reactions would result in decreased entropy?

(-3, -2) (-2, -3) (-4, -3) ?

 Can someone please solve this? ?

A sample of trifluoroacetic acid, C2HF3O2, contains 40.5 g of oxygen. Calculate the mass of the trifluoroacetic acid sample.?

Find [ (√3 + i)/2 ]⁶ + [ ( i - √3)/2 ]⁶ .?

How many moles of oxygen will occupy 728 al 760 mm Hg and 25C? please keep 3 significant figures ?

According to Reference Table V, which of these acids has the smallest ionization constant (Ka )? A) HCl B) HBr C) HNO2 D) HNO3?

 How much energy, in calories, is released as 190g water is cooled from 55.0°C to 12.0°C?

A fair coin is flipped three times. What is the probability that tails occur exactly 1 time if it is known that tails occur at least once? ?

classify each of the following as a primary secondary or tertiary alcohol?

Mathematical Induction ABC Questions?

A buffer is made by adding 0.300 mol CH3COOH nd 0.300 mol CH3COONa to enough water to make 1.000 M of solution. The pH of the buffer is 4.7?

A hiker is climbing a mountain that forms an incline angle of 65° with level ground. ?

Which of the following will not react with hydrobromic acid?

Evaluate the problem in the photo given ?

Which of the following is a covalent compound?

The ratio of the length of a rectangle to its width is 5:4. If the width is 35 cm ,find the length. ?

Sum and Difference Identities?

chemistry ?

Use the Law of Cosines to solve the triangle. Round your answers to two decimal places.?

x+2y+3z=2x-y=3x+5y-6z xyz不為0 求x:y:z=?

A(-3)且AB=5求B?

Find the relation between m and c if the line y = mx + c is a tangent to the curve y^2 = 2x?

高一條件機率

老師出的數學問題，我不會，請幫忙！

急急急!!! 4條中三化學問題, 謝謝!

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